r Doc DOC, W 1.35: 55-1146 C m a cl WAR DEPARTMENT TECHNICAL MANUAL Tr!£ LIBRARY OF THE ' AUG H UNIVERSITY Of ILLINOIS ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, . A, ■ly-i.-. '■ '»:'T ■— '• 'i'f-- ■> / MODEL M7 WAR DEPARTMENT 15 APRIL 1945 Library U. of I. Urbana-Champaign ^QX\t nocui-nent I WAR DEPARTMENT, Washin^on 25, D.C., 15 April 1945 TM55-1146, Engine, Gasoline, Marine, Chrysler Crown, Model M7, is published for the information and guidance of all concerned. A.G. 300.7 (23 Dec 44). By Order of the Secretary of War: G. C. MARSHALL Chief of Staff. Official : J. A. ULIO, Major General, The Adjutant General. Distribution : AA.F (2) ; AGE (2) ; ASF (2) ; S Div ASF (1) ; T of Opns (2) ; PE (10) ; Sub-PE (3) ; T/0 & E 55-47 (5) ; 55-500 EA, Hq & Hq Co., Major Port (Overseas) (10) ; 55-110-1 (5). For explanation of symbols see FM 21-6. N A R DEPARTMENT TECHNICAL MANUAL TM55-I146 0(/. **TT 6 ®/?/ ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 IV A R DEPARTMENT 15 APRIL 1945 Library U. of I. Urbana-Champaign CONTENTS Paragraphs Pages SECTION 1. General description and construction.. 1-2 5-14 II. Installation. 3 15-21 III. Operation. 4-7 22-23 IV. Lubrication. 8-11 24-29 V. Trouble shooting. 12-18 30-35 VI. Tests and adjustments. 19-24 36-39 VII. Repair operations. 25-30 40-42 VIII. Disassembly of engine. 31 43-45 IX. Inspection and repair of engine parts. 32-38 46-51 X. Assembly of engine. 39-40 52-55 XL Carburetor. 41-43 56-61 XII. Fuel pump. 44-46 62-63 XIII. Water pump. 47-49 64-66 XIV. Oil pump. 50-52 67-68 XV. Generator. 53-58 69-73 XVI. Generator regulator. ;... 59-61 74-79 XVII. Ignition distributor.•. 62-65 80-82 XVIII. Starting motor.. 66-69 83-87 XIX. Reverse gear and reduction gear. 70-73 88-92 Index. . 93-96 2 TM55-1146 V 0 C . ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 V7 \ . 3>5-. 3 INTRODUCTION This Manual has been published for the informa¬ tion and guidance of the operator and mechanic charged with the responsibility of operating, adjusting and repairing the Chrysler Crown Marine Engine. Arrangement of Manual. Sections I through VI contain instructions on operation, lubrication, trouble shooting and adjustment of the engine. Fits and tolerances, including maximum allow¬ able wear dimensions, are given in these proce¬ dures' to help the mechanic inspect and reclaim parts. Starting with Section VII, mechanical in¬ formation is given, covering the repairing and rebuilding of the engine and all its subassem¬ blies. Rebuilding instructions are arranged in step-by-step procedures, illustrated with “action” views. The various subassemblies of the engine are illustrated with disassembled views which show the sequence of disassembly and assembly. Identidcation of Engine. A name plate is attached to the right side of the timing gear case, showing the type, serial number and other useful infor- Engine Name Plate mation. Opposite rotation engines are designated by the letter “0” following the model number. Engines equipped with a straight drive reverse gear are designated by the letter “S” following the model number. Engines equipped'with a re¬ duction gear are designated by the letter “R” fol¬ lowing the model number. When ordering parts for the engine, or when carrying on correspond¬ ence, be sure to mention the type and serial num¬ ber of the engine. 3 TM55-n46 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 * LEFT SIDE VIEW RIGHT SIDE VIEW 36X6 Engine, Gasoline, Marine, Chrysler Crown, Model M7 4 GENERAL DESCRIPTION AND CONSTRUCTION TM55-1146 1 Section I GENERAL DESCRIPTION AND CONSTRUCTION General description. Data and specifications. 1. GENERAL DESCRIPTION a. General. The Chrysler Crown Marine En¬ gine, Model M7, is a 6-cylinder, four-stroke cycle, poppet valve, gasoline burning type with liquid cooling and pressure lubrication. When viewed from the rear (reverse gear) end, the stand¬ ard rotation engine runs clockwise and the op¬ posite rotation engine counterclockwise. When equipped with a straight drive reverse gear or a single reduction gear of any of the various ratios available, the standard rotation engine turns a I'ight hand propeller. 1). Cylinder Block and Head. The “L” head type of cylinder block and detachable head is of cast iron material. The block and the upper part of the crankcase are cast enbloc. The water jack¬ ets extend the full length of the cylinder bore to provide efficient cooling. Water is distributed along the length of the cylinder block by means of the wate'' jacketed exhaust manifold. c. Crankshaft and Bearings. The crankshaft is of drop-forged steel and is counter-weighted integral with the shaft and thoroughly balanced. The shaft is mounted in four replaceable preci¬ sion type bearings of the babbitt-on-steel type. The bearings are accessible for inspection or re¬ placement with the oil pan removed. d. Camshaft and Bearings. The forged steel camshaft incorporates the cam lobes for actuat¬ ing the valve tappets and fuel pump, and a drive gear for driving the distributor and oil pump. The camshaft is gear driven and is mounted in the cylinder block in four bearings. The three rear bearings are replaceable with the camshaft removed ; the front bearing is machined into the block. e. Connecting Rods and Bearings. The con¬ necting rods are of high grade steel, drop forged into an I-beam. The bearings are babbitt-on- steel and are of the removable precision type. The bearings are accessible for inspection or re¬ placement with the oil pan removed. Paragraph . 1 . 2 f. Pistons, Pins and Rings. The cam-ground pistons are attached to the connecting rods by floating type piston pins. Each piston carries two compression rings and two oil rings, all above the piston pins. The pistons and connecting rod as¬ semblies are removed through the top of the cyl¬ inder bore. g. Valves. Hardened steel valve seat inserts are installed in the exhaust valve ports while the intake valve seats are machined into the cylinder block. The valve stems operate in cast iron guides which are replaceable with the valves and springs removed. The valve tappets are of the “mushroom” type with self-locking adjusting screws. The valves, valve seats, guides and springs are accessible for inspection, repair of replacement with the cylinder head and valve spring covers removed. The adjusting screws are replaceable with or without the valves and springs removed and the tappets can be replaced with the camshaft removed. h. Lubrication (figs. 1, 2 and 3). Some en¬ gines are equipped with the full-flow strainer type filter and by-pass absorption type filter, others are equipped with the full-flow absorp¬ tion type filter. The engine is lubricated by oil drawn through a strainer from the oil pan by the gerotor type oil pump. The oil is forced under pressure through the full-flow type filter and the .oil cooler and then through drilled passages in the cylinder block to the camshaft bearings, crankshaft and crankshaft bearings. Through' drilled passages in the crankshaft, the oil is forced to the connecting rod bearings, the reverse gear and reduction gear assembly. Oil is forced in a limited quantity from the rear camshaft bearing directly onto the timing gears. The cam¬ shaft thrust plate is lubricated by oil through a passage in the camshaft. The cylinder walls, pistons, piston pins and valve tappets are lubri¬ cated by oil spray from metered holes in the con¬ necting rod lower bearings. Oil is bypassed through an absorption type filter (on engines 5 TM55-1146 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Figure 1—Engine Oiling System 6 TM55-1146 GENERAL DESCRIPTION AND CONSTRUCTION OIL GROOVE MACHINED IN CRANKSHAFT BEARINGS OIL PASSAGES DRILLED IN CRANKSHAFT OIL PASSAGES ARE DRILLED IN THE CRANKSHAFT FROM THE MAIN BEARINGS TO THE CONNECTING ROD BEARINGS. THESE OIL PASSAGE OPENINGS REVOLVE WITH THE CRANKSHAFT BUT ARE SUPPLIED WITH AN UNINTER¬ RUPTED FLOW OF OIL FROM THE CIRCULAR OIL GROOVE MACHINED IN THE CRANKSHAFT BEARINGS OILER PLUG THE TIMING GEARS ARE OILED THROUGH A PASSAGE DRILLED FROM THE REAR FACE OF THE CYLINDER BLOCK TO THE CAMSHAFT REAR BEARING INTO WHICH A SHORT TUBE IS INSERTED THAT DIRECTS THE OIL TO THE TIMING GEARS. A DRILLED PLUG THREADED INTO THE REAR END OF THE CAMSHAFT OIL PASSAGE DIRECTS OIL TO THE REVERSE GEAR AND SINGLE REDUCTION GEAR. 36x3 Figure 2—Engine Oiling System—Connecting Rod Bearings and Timing Gears 7 TM55-1146 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 AS THE CRANKSHAFT REVOLVES AND THE OIL HOLE DRILLED IN EACH CONNECTING ROD PASSES THE OIL PASSAGE IN THE CRANKSHAFT, A SPRAY OF OIL IS RELEASED TO THE CYLINDER BORE WALLS, PISTON PINS AND VALVE TAPPETS. VALVE TAPPETS OIL HOLES ARE DRILLED IN THE CYLINDER BLOCK AT EACH VALVE TAPPET TO ALLOW THE OIL SPRAYED FROM THE OIL HOLE IN THE CONNECTING ROD LOWER BEARINGS AND COLLECTED IN OIL RESERVOIRS TO REACH THE VALVE TAPPETS. AN OIL HOLE IS DRILLED IN THE TOP OF EACH CONNECTING ROD THROUGH WHICH OIL SPRAYED FROM THE OIL HOLE IN THE CONNECTING ROD LOWER BEARINGS CAN REACH THE CONNECTING ROD PISTON PIN BUSHING. OIL IS SUPPLIED TO THE CAMSHAFT THRUST PLATE THROUGH AN OIL PASSAGE DRILLED IN THE REAR END OF THE CAMSHAFT THAT OBTAINS ITS SUPPLY OF OIL AS IT REVOLVES PAST THE CYLINDER BLOCK OIL PASSAGE OPENING. 36x4 Figure 3—Engine Oiling System—Pistons, Piston Pins, Valve Tappets and Camshaft 8 TM55-1146 1 GENERAL DESCRIPTION AND CONSTRUCTION so equipped), where fine particles of foreign material are separated from the oil. Oil pressure is controlled by a relief valve attached to the main oil passage on the right side of the engine. i. Cooling (fig. 4). There are two types of engine cooling systems in general use; some en¬ gines are cooled directly by the sea water in which the craft operates, others are cooled by a self-contained system incorporating the use of a heat exchanger. (1) Sea Water Cooling System. The gear type water pump draws water from the sea and forces it through the oil cooler. The oil cooler acts in the capacity of a heat exchanger in that the heat from the engine lubricating oil circulat¬ ing around the pipes of the cooler is transferred to the water passing directly through the tubes, thus lowering the temperature of the oil and rais¬ ing the temperature of the cold water before it is passed into the engine. From the oil cooler, the A'ater passes through a water jacket around the exhaust manifold and is then circulated through water jackets in cylinder block and head from where it is discharged, usually into the exhaust outlet pipe, and returned to the sea, carrying with it the heat generated by the engine com¬ bustion which cannot be converted into power. A by-pass valve incorporated in the water outlet connection at the cylinder head provides a means of returning warm water to the suction side of the pump to regulate the temperature of water entering the pump. (2) Self-Contained Cooling System. A heat exchanger should be connected between the outlet pipe at the cylinder head and the suction side of the engine cooling pump. The coolant contained in the system is circulated by the pump through the oil cooler, manifold water jacket and the cylinder water jackets, then to the heat ex¬ changer and back to the pump. Heat developed by combustion in the engine and not converted into power is carried by the self-contained cool¬ ant to the heat exchanger where it is transferred to the cold sea water and dissipated in the sea. j. Crankcase Ventilation. The crankcase ven¬ tilation system is designed to remove harmful fumes from the crankcase and to prevent con¬ densation of these fumes, which cause excessive dilution of the engine oil. Ventilation is accom¬ plished by drawing off the fumes or vapors through the crankcase ventilator pipe which serves as a support for the air silencer and flame 36 X 1 EXHAUST MANIFOLD WATER OUTLET OIL COOLER WATER INTAKE WATER PUMP Figure 4—Sea Water Cooling System 9 TM55^1146 1-2 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 arrester assembly. Fresh air is drawn into the crankcase through the air vent located on the reverse gear cover. The crankcase ventilation system requires no maintenance attention other than cleaning the flame arrester occasionally. 2. DATA AND SPECIFICATIONS a. Engine—General. Make.Chrysler Crown Model.M7 Type.“L” head Number of cylinders. tn.6 Cylinder bore.SFio in. Stroke..41/? in. Piston displacement.250.6 cu. in. Compression ratio.6.8 to 1 Compression pressure at cranking speed (125 rpm).115 to 125 lbs Maximum torque (fig. 5) .208 ft lbs at 1600 rpm Brake horsepower (net) (fig. 5).109 at 3000 rpm Firing order (standard rotation) . . . .1-5-3-6-2-4 (opposite rotation).1-4-2-6-3-5 (No. 1 cylinder is at flywheel end of engine.) b. Cylinder Block and Head. Type.“L” head Material.Gray iron Cylinder bore.3.4575 in. Cylinder bore taper (maximum allowable) .0.020 in. Cylinder bore out-of-round (maximum allowable).0.005 in. Torque wrench pull on cylinder head stud nuts.55 to 60 ft lbs c. Camshaft. Material .Forged steel Drive.Gear Number of bearings.4 Type of bearings.3 steel backed babbitt 1 cast iron (polished in block) Thrust taken by.Thrust plate Bearing Journal Diameter: No. 1 (front) .1.247 to 1.2480 in. No. 2 (front intermediate) 1.934 to 1.9350 in. No. 3 (rear intermediate) .1.9655 to 1.9665 in. No. 4 (rear) . . .;.1.9987 to 1.9980 in. Bearing journal wear (maximum allowable).0.002 in. Camshaft Bearing Clearance: Standard.0.002 in. Maximum allowable.0.004 in. Camshaft End Play: Standard.0.002 to 0.006 in. Maximum allowable.0.010 in. Camshaft Bearing Diameter: No. 1 (front) .1.250 to 1.2510 in. No. 2 (front intermediate) 1.9375 to 1.9385 in. No. 3 (rear intermediate) .1.9690 to 1.9700 in. No. 4 (rear).2.000 to 2.0010 in. Maximum allowable wear.0.002 in. d. Crankshaft and Bearings. Number of bearings. * .4 Type.Replaceable precision Material.Babbitt-on-steel Thrust taken by.Front main bearing Crankshaft Bearing Journal Diameter: Standard.2.4995 to 2.5002 in. Maximum allowable wear.0.002 in. Maximum allowable taper or out-of-round.0.001 in. 36x9 Figure 5—Power Curve 10 TM55-1146 2 GENERAL DESCRIPTION AND CONSTRUCTION Connecting Rod Bearing Journal Diameter: Standard . .2.126 to 2.1246 in. Maximum allowable wear .0.002 in. Maximum allowable taper or out-of-round. .0.001 in. Crankshaft bearing clearance. .0.0005 to 0.0025 in. Crankshaft End Play: Standard.. . .0.003 to 0.007 in. Maximum allowable. .0.010 in. Crankshaft run-out (maximum' allowable).0.002 in. at center journal Fillets. %2 to %2 in. radius Torque wrench pull on main bearing cap screws.75 to 80 ft lbs e. Connecting Rods and Bearings. Material.High grade steel Center-to-center length. 7% in. Piston pin bushing material.Bronze Bearing type.Removable precision Bearing material.Babbitt-on-steel Connecting Rod Bearing Clearance: Standard.0.0006 to 0.0026 in. Maximum allowable.0.0026 in. Connecting rod twist or bend (maximum allowable).0.0025 in. Torque wrench pull on bearing bolts.. 45 to 50 ft lbs f. Pistons. Type.Cam ground Length. 31/2 Length from top of piston to center of pin. . 2 in. Piston ring groove depth— compression.0.177 in. Piston ring groove depth—oil.0.179 in. Clearance—top land.0.019 to 0.024 in. Total cam.0.0035 to 0.0045 in. Taper of skirt.0.001 to 0.0015 in. Skirt clearance (thrust side). . 6 to 8 lbs pull with 0.002 X 1/2 in. feeler at 70° F. g. Piston Pins. Type.Floating Material.High manganese steel Length.2% in. Bearing. . .In piston and connecting rod bushing Diameter .0.8591 to 0.8593 in. Fit in connecting rod.So that pin will fall through rod when rod is shaken Fit in piston. . . Medium thumb push fit at 70° F. h. Piston Rings. Compression Rings: Number per piston.2 Width. %2 in. Oil Rings: Number per piston.2 Width.% 2 in. Compression Ring Side Clearance: Top (standard).0.002 to 0.004 in. Second (standard).0.002 to 0.0035 in. Maximum allowable.0.008 in. Oil Ring Side Clearance: Standard.0.001 to 0.002 in. Maximum allowable.0.004 in. Gap: Standard.0.007 to 0.015 in. Maximum allowable. 0.030 in. i. Valves, Guides, Springs and Tappets. Type.'. Location. Style of stem end. Valves—Material: Intake. Exhaust. Port Diameter: Intake . Exhaust. Head Diameter: Intake.; . . . . Exhaust . Valve length. Seat angle. Width of valve seat. Exhaust valve seat material Valve lift. Guides: Type. Material.,. Springs—type. .Poppet Left side of engine .Ring grooved .Alloy steel .Silchrome .1.708 in. .1.637 in. . Wig in. . Wg 2 in. .4“%2 in. .45 degrees ....... .y^G to %2 in. .Chromium tungsten steel .0.379 in. .Removable .Cast iron . . Cadmium plated or stainless steel Tappets: Type.Mushroom, self-locking adjusting screw Material.Stem—high manganese steel Head—face—puddled alloy iron Stem diameter.% in. 11 TM55-1146 2 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Valve Stem Clearance in Guide: Intake: Standard.. ,0.0015 to 0.0035 in. Maximum allowable.. . .0.005 in. Exhaust: Standard . ,. .0.003 to 0.005 in. Maximum allowable.. . .0.007 in. Valve Stem Diameter: Intake (standard). ,0.340 to 0.341 in. Exhaust (standard). 0.3385 to 0.3395 in. Maximum allowable wear .0.002 in. Valve Stem Guides: Ream to. ,0.3425 to 0.3435 in. Distance from top of cylinder block to top of valve guide.. . .% in. Valve Spring Pressure at Length of: 1 %, in. (closed). . 40 to 45 lbs 1 % in. (open). .107 to 115 lbs Tappet Stem Diameter: Standard . ,0.6235 to 0.6240 in. Maximum allowable wear .0.001 in. Tappet Stem Clearance in Guide: Standard . Maximum allowable. .0.002 in. Tappet Clearance: Intake: Hot . .0.010 in. Cold. .0.010 in. Exhaust: Hot . .0.012 in. Cold. .0.014 in. j. Timing Gears. Gear Backlash: Standard .0.002 to 0.004 in. Maximum allowable.0.010 in. Shaft Bore: Standard.0.4865 to 0.4875 in. Maximum allowable wear.0.003 in. Cover gasket thickness.0.038 to 0.042 in. Length of Rotors: Standard.0.749 to 0.750 in. Maximum allowable wear.0.002 in. Outer Diameter of Outer Rotor: Standard.2.446 to 2.475 in. Maximum allowable wear.0.002 in. Diameter of Pump Shaft: Standard.0.4853 to 0.4858 in. Maximum allowable wear.0.003 in. End Play: Standard. 0.003 to 0.008 in. Maximum allowable.0.003 in. m. Fuel. Octane rating 70 to 80 n. Carburetor. Make. Model. Type. Throttle bore Float setting. Idle jet. Main jet. Main jet. Idling jet. Discharge tube jet Cap jet. Suction jet. Compensating jet. ..Zenith .556-M3 .Updraft .IV 2 in. 2% in. from gasket surface of body to top edge of float with float valve on seat .Ad j ustable .Adjustable .No. 29 ...No. 11 .No. 17 .No. 32 ..No. 15 .No. 32 k. Engine Oiling System. Type.Pressure Pressure at which relief valve opens. 40 to 45 lbs Oil pump intake.Floating screen l. Oil Pump. Make.Chrysler Type.Gerotor * Capacity pressure.40 lbs at 250 rpm with SAE 30 oil at 200° F. Inner Diameter of Body: Standard.2.250 to 2.252 in. Maximum allowable wear.0.002 in. Depth of Body: Standard.0.751 to 0.752 in. Maximum allowable wear.0.002 in. o. Fuel Pump. Make. Part number. Operating pressure.... p. Water Pump. Make. Type. Method of packing. q. Generator. (1) 6-volt Generator Make. Model: For standard rotation For opposite rotation. Capacity. .AC . . 1537228 3 to 41/2 lbs .Chrysler . ... Dual drive Gland and nut .Auto-Lite .GGE 4804M .GGE 4805M 6-volts, 12 ampere 12 TM55-1146 2 GENERAL DESCRIPTION AND CONSTRUCTION (1) 6-volt Generator, Contd. Maximum Allowable Voltage Loss in Generating Circuit; 10 amps flowing in circuit.0.35 volts Field coil draw.1.7 to 1.9 amps at 6 volts Motorizing draw.3.0 to 3.4 amps at 6 volts Brush spring tension.45 to 53 oz Maximum allowable eccentricity of commutator .0.002 in. (2) 12-volt Generator Make.Auto-Lite .Model: For standard rotation.GEF 4809M For opposite rotation.GEF 4810M Capacity.12-volts, 18 ampere Maximum Allowable Voltage Loss in Generating Circuit: 10 amps flowing in circuit.0.35 volts Field coil draw.... 1.35 to 1.50 amps at 13.0 volts Motorizing draw. . .3.35 to 3.7 amps at 13.0 volts Brush spring tension.64 to 68 oz Maximum allowable eccentricity of commutator.0.002 in. r. Generator Regulator. (1) 6‘volt Regulator Make .Auto-Lite Model .VRW-4101AM Amperage.12 Voltage .6 Polarity.Positive Carbon Resistor: Resistor marked 30.28.0 to 32.0 ohms Circuit Breaker: Resistance of winding.29.8 to 33.0 ohms Armature air gap.0.031 to 0.034 in. Length of armature spring.10% turns Minimum contact point gap.0.015 in. Points close at.6.4 to 7.0 volts Points open at.4.1 to 4.6 volts after a charge of 10 amps Voltage Regulator: Resistance of winding.10.8 to 12.0 ohms Armature air gap.0.048 to 0.052 in. Length of armature spring.14V2 turns Minimum contact point gap.0.012 in. Operating voltage at room temperature...7.1 to 7.3 volts Current Regulator: Armature air gap.0.048 to 0.052 in. Length of armature spring.10% turns Minimum contact point gap.0.012 in. Operating amperage.11.0 to 13.0 amps (2) 12-volt Regulator Make.Auto-Lite Model.VRS-4102AM Amperage.18 Voltage .12 Polarity.Positive Carbon Resistor: Resistor marked 60.57.0 to 63.0 ohms . Circuit Breaker: Resistance of winding. .. . 111.0 to 125.0 ohms Armature air gap.0.031 to 0.034 in. Length of armature spring.10% turns Minimum contact point gap.0.015 in. Points close at.13.0 to 13.75 volts Points open at.8.2 to 9.3 volts after a charge of 10 amps Voltage Regulator: Resistance of winding.43.7 to 49.3 ohms Armature air gap.0.048 to 0.052 in. Length of armature spring.14 V 2 turns Minimum contact point gap.0.012 in. Operating voltage at room temperature.14.3 to 14.6 volts Current Regulator: Armature air gap.0.048 to 0.052 in. Length of armature spring.10% turns Minimum contact point gap.0.012 in. Operating amperage.16.0 to 18.0 amps s. Ignition Distributor. Make.Auto-Lite Model.IGC-4723-IM Breaker point gap.0.020 in. Cam angle (point dwell).37 V 2 to 40 degrees Ignition timing... 2 degrees or 0.002 in. B.T.D.C. Breaker arm spring tension.17 to 20 oz Maximum allowable drive shaft bushing wear.0.008 in. Governor Advance: At 350 distributor rpm. 0 degrees* At 400 distributor rpm. 3 degrees* At 650 distributor rpm. 5 degrees* At 900 distributor rpm. 7 degrees* At 1150 distributor rpm. 9 degrees* At 1400 distributor rpm (max.) . .11 degrees* At 700 engine rpm. 0 degrees** At 800 engine rpm. 6 degrees** At 1300 engine rpm.10 degrees** At 1800 engine rpm.14 degrees** At 2300 engine rpm.18 degrees** At 2800 engine rpm (max.).22 degrees** ‘Tolerance—plus or minus one distributor deKree. “Tolerance—plus or minus two engine degrees. 13 TM55-1146 2 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 t. Spark Plugs. Make.Auto-Lite or Champion Type (Auto-Lite).BH4-B Type (Champion).6 comm. 62 Size.18 mm Gap .0.025 in. u. , Starting Motor. (1) 6-volt Starting Motor Make.Auto-Lite Model: For standard rotation.MAW 4008-M For opposite rotation.MAW 4007-M Drive.Bendix Switch.Solenoid operated Armature end play.%4 in. Voltage .6 No load current draw—volts.5.5 amps.. . 65 speed.4900 rpm (2) 12-volt Starting Motor Make.Auto-Lite Model: ' For standard rotation.MAY 4134-M For opposite rotation.MAY 4130-M .Drive . . . ..'.Bendix Switch.Solenoid operated Armature end play.. %4 in. Voltage . 12 No load current draw—volts.11 amps.30 speed.5300 rpm V. Reverse Gear and Reduction Gear. Make.Chrysler Type of reverse gear.Planetary Type of reduction gear.Internal gear and pinion Mainshaft bearings.Ball and bushings Pinion bushings.Oil-lite Number of pinions.6 Number of clutch plates.4 steel and 4 brass \ 14 TM55-1146 3 INSTALLATION Section II INSTALLATION Installation of engine Paragraph . . 3 3. INSTALLATION OF ENGINE a. Inspection of Shipment. The Chrysler Crown Marine Engine is carefully tested and inspected before shipment from the factory. It is ready for normal operation when properly in¬ stalled and serviced. See paragraph 4. When the engine is shipped from the factory, it is mounted on heavy skids and properly crated. Immediately upon arrival at destination, inspect the shipment for possible damage in transit and shortage of parts or equipment. b. Engine Bed. A good engine bed is an im¬ portant factor in satisfactory engine operation. The maximum operating angle of the engine should not exceed 15 degrees. Use an engine bed of sufficient rigidity to support the engine under all operating conditions. Use engine mounting bolts of sufficient size to avoid possible shifting of the engine which would result in misaline- ment between the engine and propeller shaft. See installation diagrams (figs. 6, 7, 8, 9, 10, 11 and 12). c. Engine Alinement (fig. 13). The aline- ment of the engine with the propeller shaft is the most important consideration when installing the engine, as misalinement will result in exces¬ sive vibration, loss of power and speed and exces¬ sive wear. The two halves of the propeller cou¬ pling must come together parallel within 0.002 inch with the flange bolt holes in perfect aline¬ ment. Hold the halves of the coupling together and check for parallelism of the halves with a thin feeler gage. If necessary, shift or shim the engine to get perfect alinement with the pro¬ peller shaft at time of installation. Make the final alinement check with the boat in the water. Figure 6—Installation Diagram V-Drive (1.43 to 1 Reduction Gear) 15 TM55-1146 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Figure 7—Installation Diagram (1.95 to 1 Reduction Gear) Figure 8—Installation Diagram (2.05 to 1 Reduction Gear) 16 TM55-1146 3 INSTALLATION d. Fuel Tank and Connections. (1) Fuel Tank. The fuel tank may be lo¬ cated either above or below the engine, but pref¬ erably below. If the tank is installed higher than the carburetor, install a shut-off valve in the fuel pipe as close as possible to the main fuel tank. The tank should be provided with an out¬ side vent adequately protected against the ele¬ ments. Install a drain plug at the lowest point of the tank. (2) Connections. Use % inch outside diameter tubing with a short section of flexible tubing between the feed line and the fuel pump to absorb vibration and prevent fuel line breakage. e. Water Connections (Direct Sea Water Cooling System). (1) Intake. The intake pipe from the water scoop should be as straight as possible and should have an inside diameter of not less than % inch to insure an adequate supply of water to the engine. Install at least one length of non-collapsible rubber hose in the pipe to absorb vibration. If a sea-cock or valve is in- Figure 9—Installation Diagram (2.56 to 1 Reduction Gear) Figure 10—Installation Diagram (3.46 to 1 Reduction Gear) 17 TM55-n46 3 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 stalled in the intake line for emergency use, it should be of a free-flow type and of sufficient size to prevent obstruction to the flow of water. (2) Outlet. Various methods for the proper introduction into the exhaust pipe of the water leaving the engine, are shown in figure 14. To prevent damage to the engine, it is essential that the entrance of the water into the exhaust pipe be so arranged as to eliminate water getting back into the manifold. However, the connection should be made as close to the manifold as is practical to make the uncooled section of the exhaust pipe as short as possible. Connection to the water outlet pipe on the engine cylinder head should be made with a short length of non- collapsible rubber hose to absorb vibration. Figure 11—Installation Diagram (4.9 to 1 Reduction Gear) Figure 12—Installation Diagram (Straight Drive) 18 1 TM55-1146 3 INSTALLATION FLANGES MUST BE PARALLEL WITHIN 0.002-IN 32 X 151 WATER OUTLET FROM ENGINE WATER JACKET CLOSE TO ENGINE Figure 13—Alinement of Engine and Shaft (3) Temperature Control. The water tem¬ perature by-pass control valve located on the forward end of the cylinder head is tapped for % inch American National Standard pipe thread. The pipe line running from this valve should be connected below the water line to a fitting just inside of the water scoop as shown in figure 15. A short length of non-collapsible rubber hose should be installed in the line to absorb vibration. f. Water Connections (Self-contained Cool¬ ing System). The pipe connections made from the engine intake and outlet to the heat exchang¬ er should be of not less than % inch inside diam¬ eter and as straight'as possible to insure an ade¬ quate supply of water to the engine cooling sys¬ tem. A short length of non-collapsible rubber hose should be installed in the line to absorb vibration. g. Electrical Connections (figs. 16 and 17). The electrical system should be properly con¬ nected to insure satisfactory operation. Mount the battery and generator regulator close to the engine and make certain that the base of the regulator is definitely grounded. Use only well insulated waterproof wire and cable of the sizes shown in figures 16 and 17. Undersize or low capacity wires will not carry the amount of cur¬ rent required for proper operation of the electri¬ cal units. Make wire connections as short as pos¬ sible and locate the wires where they will not get wet or become damaged by rubbing against con¬ trols or other moving parts. STREET ELL INSIDE OF EXHAUST PIPE TO DEFLECT WATER AWAY FROM ENGINE USE 45 DEGREE ELBOWS—NEVER 90 DEGREE ELBOWS SCREWED PIPE EXHAUST TYPE USED WHEN ENGINE IS LOCATED BELOW WATER LINE 32 X 152 Figure 14—Exhaust Cooling Connections 19 TM55-n46 3 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 BY-PASS CONTROL VALVE CLEAN OUT . PLUG\ WATER PUMP PUMP SUCTION WATER LINE NOTE:- THIS FITTING MUST BE LOCATED BELOW WATERLINE RETURN FROM ENGINE WATER OUTLET BY-PASS CONTROL VALVE ENGINE WATER OUTLET TO EXHAUST PIPE AND OVERBOARD HULL 32 X 153 Figure 15—Water Temperature Control Connection Figure 16—Wiring Diagram (6-Volt System) h. Controls and Instruments. (1) Controls. Install a sturdy throttle con¬ trol lever and linkage that will operate the car¬ buretor throttle without lost motion or binding. Install the choke control so that it works freely 1 2 3 4 5 6 Figure 17—Wiring Diagram (12-VoIt System) with sufficient travel to fully close and fully open the choke. (2) Oil Pressure Gage. Connect the gage to the pressure side of the engine oiling system. 20 TM55-1146 3 INSTALLATION Use a inch outside diameter tube with a short section of flexible tubing next to the engine to absorb vibration and prevent possible tube failure. (3). Water Temperature Gage. Locate the water temperature gage so that with the bulb in the cylinder head, the tube will be free of kinks and anchored to prevent chafing against other parts. i. Exhaust System. (1) General. The requirements for the ex¬ haust system are to provide an outlet line with a minimum of restriction and to prevent sea water getting into the engine. (2) Size and Slope of Pipe. The exhaust pipe should be at least the size of the manifold flange opening. There should be considerable fall between the manifold and the discharge end of the pipe to prevent water being driven in the manifold and engine by a following sea. A 45- degree drop followed by a long gradual slope is better than a straight gradual slope. Do not use 90-degree elbows in the exhaust pipe. (3) Flexible Sections and Supports. An exhaust line longer than six feet should be prop¬ erly supported to avoid strain on the exhaust manifold. The exhaust pipe should have at least one flexible connection. In long pipes, two flex¬ ible sections are needed to eliminate noise and vibration and to avoid undue strain on the ex¬ haust manifold. (4) Muffler. If a muffler is used, it must be of ample capacity and should be located near the discharge end of the exhaust pipe. I TM55-1146 4-6 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section HI OPERATION Paragraph . . 4 . . 5 . . 6 . . 7 Preparation of new engine for operation Prestarting inspections Starting and stopping the engine Operating precautions 4. PREPARATION OF NEW ENGINE FOR OPERATION a. General. Before placing a new or rebuilt engine in service, make a thorough inspection for evidence of damage or looseness of parts, giving particular consideration to the following items: (1) Engine Oil. See that the oil pan con¬ tains a sufficient amount of oil of the recom¬ mended viscosity. See paragraph 8. (2) Engine Accessories. Make sure all points requiring lubrication are supplied with lubricant. See paragraph 11. (3) Cooling System. If the engine is equipped with a self-contained cooling system, see that the system is filled with clean water. During freezing weather, use a sufficient amount of anti-freeze to protect the system for the low¬ est anticipated temperature. (4) Battery and Electrical Connec¬ tions. See that all electrical connections, par¬ ticularly battery cables, are properljr and se¬ curely connected. See that the battery contains sufficient electrolyte solution. See paragraph 21. (5) Cylinder Head Nuts; Bolts and Cap Screws. See that all cap screws, bolts and nuts which hold attaching par.ts are securely ^tight¬ ened. Tighten cylinder head nuts as described in paragraph 39 m. 5. PRESTARTING INSPECTIONS a. General. The life of an engine depends to a great extent upon the kind of care and atten¬ tion it receives. The use of the correct grade and quantity of lubricating oil in the crankcase is an important factor in lengthening the useful life of the engine. When the engine is in constant use, make the following inspections daily. If the en¬ gine has been idle for a period of time, make the inspections before the engine is started. (1) Engine Oil Level. Inspect the engine oil for proper level. Add oil as required. (2) Fuel. Use fuel of 70 to 80 octane rating. When fuel of a higher rating is to be continu¬ ously used, it is recommended that the engine be equipped with sodium cooled exhaust valves. (3) Leaks. Inspect the engine in general for evidence of fuel, oil or water leakage. (4) Drain Cocks. Make certain all water drain cocks are closed. (5) Cooling System (Self-contained Type) . Inspect level and add fluid as required. 6. STARTING AND STOPPING THE ENGINE a. Starting the Engine. (1) Perform prestarting inspections. See paragraph 5. (2) Set the throttle at ^5 opening and pull out the choke button. (3) Make sure the reverse gear lever is in the neutral position and turn on the ignition switch. (4) Press the starting motor switch until the engine starts but for not longer than fifteen sec¬ ond periods at a time. (5) If the engine does not start at the first attempt, allow ten to fifteen seconds time to elapse and repeat steps (1) through (4) above. (6) If the engine becomes over-choked or flooded, push the choke button in, open the throt¬ tle fully, and press the starting motor switch. After the engine starts, watch the oil pressure gage. If oil pressure is not built up immediately, stop the engine and investigate the cause. (7) Make certain that water circulates im¬ mediately after the engine is started. This may be determined by noting if water discharges 22 OPERATION TM55-1146 6-7 through the exhaust pipe outlet, or by noting the change in exhaust noise which will be muffled as soon as water begins to circulate. It may be neces¬ sary to operate the engine at approximately 1000 revolutions per minute to start the water circu¬ lating. b. Stopping the Engine. Close the throttle gradually and disengage the clutch. Allow the engine to run at idling speed for approximately fifteen to twenty seconds. Then, with the throttle closed, turn off the ignition. This procedure will prevent kick-back and the drawing of steam vapor from the exhaust pipe into the combustion chambers. 7. OPERATING PRECAUTIONS a. Warm-up Period. After starting a cold engine, operate it at a speed slightly faster than idle (approximately 700 revolutions per minute) for a few minutes to allow it to warm up before placing it in service. Allow the engine to reach normal operating temperature (subpar. c below) before placing it under full load. This will allow the oil to warm and reach the bearing surfaces. and reduce the possibility of scoring and prema¬ ture wear of internal engine parts. b. Oil Pressure. With the engine turning at 1400 revolutions per minute and the water at normal operating temperature, the oil pressure is maintained at 30 to 45 pounds, providing there is no unusual escape of oil from some point in the system. As bearings wear and the increased clearance allows more than the normal amount of oil to escape, there will be a drop in pressure shown on the gage, particularly at idling speed. Determine the cause for pressure drop and make the necessary corrections. c. Water Temperatures. (1) Sea Water Cooling System. If the water temperature exceeds 200° F, stop the en¬ gine and investigate the air and water circula¬ tion (par. 13 e). (2) Self-contained Cooling System. If the water temperature exceeds 200° F, stop the engine and investigate the air and water circula¬ tion (par. 13 f). 23 TM55-1146 8-10 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section IV LUBRICATION Paragraph Engine oil. 8 Air silencer and flame arrester. 9 Oil filters and cooler. 10 Lubrication of engine accessories. 11 8. ENGINE OIL a. Oil Recommendations. It is important to use oil of the highest .quality and of the proper viscosity to insure adequate lubrication of mov¬ ing parts. See War Department Lubrication Order for proper lubricants and grade. b. How to Change Engine Oil (fig. 18). Change the oil when the engine is hot, as the oil will drain down into the oil pan more readily and carry off foreign material and sediment more completely. Remove the plug from the right side of the reduction gear case and remove the oil level indicator. Screw the oil level indicator guide out of the boss on the oil pan. Insert the hand-operated suction pump, furnished as a part of the engine equipment, through the openings and into the bottom of the oil pan and gear case. Remove the oil with the suction pump and refill with the proper grade of oil. If it becomes neces¬ sary to flush the engine lubrication system, use clean engine oil. Do not use kerosene or light flushing oil, as a certain amount of such oil will remain in the engine and dilute the new oil. c. Checking and Adding Engine Oil (fig. 18). The oil level indicator is of the bayonet type marked “FULL” and “EMP” (empty). Check the oil level daily before starting the engine. If the oil level is lower than 14 below the full mark, add sufficient oil to bring the level to the “full” mark. CAUTION: The engine should not be operated with the oil level lower than niuhvay betiveen the “fidl” and “empty” marks. Figure 18—Oil Removal Hole Plugs and Oil Level Indicator 9. AIR SILENCER AND FLAME ARRESTER Remove the screws which attach the air horn to the body and remove the air horn (fig. 19). Wash the element in dry-cleaning solvent and dry thoroughly before installing the assembly. 10. OIL FILTERS AND COOLER a. General. The engine is equipped with oil filters to remove dirt and foreign material from the oil. Cooling of the oil is accomplished through the use of an oil cooler. Some engines were supplied without the oil cooler, with the arrangement of the oil and water tubes as shown in figure 20. 24 TM55-1146 10 LUBRICATION AIR HORN TO BODY ATTACHING SCREWS 32x48 Figure 19 —Carburetor Air Silencer and Flame Arrester b. By-pass Absorption Type Oil Filter (fig. 21 ). (1) Description. When the oil passes through the filter, the foreign substances are trapped in the filtering cartridge. This process is continuous and the cartridge will continue to trap dirt until it becomes clogged. When the car¬ tridge becomes clogged it ceases to filter the oil and should be replaced. Replace the cartridge after each 250 hours of operation, or as often as necessary to keep the oil clean. (2) Replacement of Filter Cartridge. Remove the cover and lift out cartridge. Place new cartridge in case, use new gasket and install cover. c. Full-flow Strainer Type Oil Filter (fig. 22). (1) Description. When the oil passes through the filter, dirt and foreign material set¬ tle in the bottom of the filter body and also ac¬ cumulate on the filter element. A relief valve is placed in the filter head to bypass the oil when the pressure becomes too great. (2) Cleaning Filter Element. Turn the handle on top of the filter 3 to 5 complete revolu¬ tions clockwise after each 8 hours of operation. Remove the drain plug from bottom of filter body OIL COOLER WATER OUTLET OIL COOLER 1. WITH OIL COOLER 2. WITHOUT OIL COOLER 36x65 Figure 20—Schematic Drawing of Oil Filter and Oil Cooler Installation 25 TM55-n46 10 engine/GASOLINE, MARINE/ CHRYSLER CROWN, MODEL M7 and drain filter after each 25 hours of operation. Always use a new gasket when installing the drain plug and tighten plug securely to prevent an oil leak. Figure 21—By-pass Absorption Type Oil Filter d. Full-flow Absorption Type Filter (fig. 23). (1) General. When the oil passes through the filter, the foreign substances are trapped in the filter elements. This process is continuous and the elements will continue to trap dirt until they become clogged. Due to a spring loaded relief valve in the filter base, the clogging of the filter elements will not stop the circulation of oil to the bearings. When the elements are clogged, however, they cease to filter the oil and should be replaced. Replace the elements after each 250 hours of operation, or as often as necessary to keep the oil clean. (2) Remove Filter Elements. Remove the drain plug from the bottom of the filter body and drain oil from'filter. Remove the large acorn retaining nut and lift off the filter cover. Remove filter elements from the filter body. (3) Clean Filter Body. Remove the hexa¬ gon plug opposite the pump to filter pipe connec¬ tion and remove the relief valve, spring and plunger. Clean the interior of the filter body and oil passages thoroughly. (4) Install Relief Valve. Clean and in¬ stall the relief valve plunger, spring and plug. (5) Inspect Gaskets and Install Filter Elements. Inspect the filter body gaskets and replace if necessary to provide a good seal. Place GASKET o -RELIEF VALVE PLUG ■RELIEF VALVE SPRING -RELIEF VALVE BALL -HANDLE PACKING NUT NUT AND LOCKM/ASHER KNIFE FILTER ELEMENT DRAIN PLUG GASKET HEAD RETAINER RING HEAD CASE GASKET DRAIN PLUG 32X148 Figure 22—Full-flow Strainer Type Oil Filter 26 TM55-1146 10 LUBRICATION the body cylinder in place on the lower gasket and install the filter elements over the outlet sleeves at the bottom of the filter. Install the cover with the depressions in the cover over the upper ends of the filter elements. Install metal gasket and the cover retaining nut and tighten the nut to a-tension of 50 foot pounds. (6) Bleed Air From Filter. Open the bleed cock at the top of the filter and run the engine slowly, for a few seconds, to bleed air from the filter. As soon as oil is discharged from the bleed cock, close the cock securely and inspect for oil leakage at the filter body gaskets. Do not tighten the cover retaining nut tighter than 50 foot pounds to overcome a leak at a gasket; replace the gasket instead. DRAIN PLUG 32x49 COVER RETAINING NUT- WASHER AIR BLEEDER COVER BODY GASKET \ BODY COVER STUD FILTER ELEMENTS STAND PIPE ELEMENT PILOTS BODY GASKET BASE RELIEF VALVE PLUG GASKET SPRING li PLUNGER Figure 23—Full-flow Absorption Type Oil Filter e. Oil Cooler (fig. 24). (1) Maintenance. Remove the zinc elec¬ trode (if so equipped) once every 90 days for inspection. Replace the electrode if 50 per cent disintegrated. Excessive corrosion of the elec¬ trode indicates electrolytic action and careful inspection should be made to determine if this action is caused by short circuits or external grounded electric currents. If so, this condition must be eliminated to avoid the necessity of fre¬ quent replacement of electrode. If no such condi¬ tions are found, it will be evident that corrosion is due to local electrolysis. Upon inspection, the electrode may be found to be coated and corroded with insulating foreign material. This should be removed by wire brushing and scraping before installing the electrode. (2) Cleaning. (a) Frequency of Cleaning. The oil cooler should be cleaned as frequently as necessary to provide unrestricted flow of water and oil. In certain types of service, oil sludge and carbon formation is more rapid than in others. Heavy deposits of sludge and carbon will cause a de¬ crease in cooling efficiency, therefore the fre¬ quency of cleaning will vary, depending upon operating conditions. (b) Clean Oil Passages of Cooler. If the cooler requires cleaning, remove it from the en¬ gine, remove both covers and zinc electrode (if so equipped) and inspect for oil sludge and carbon formation (fig. 24). Circulate a dry-cleaning sol¬ vent through the oil passages with a hand or motor driven pump, in reverse direction from normal operating flow. Continue this action until the unit is clean. If a circulating pump is not available, immerse the body in a container of dry-cleaning solvent. After the unit has been allowed to stand in the solvent for a few minutes, force cleaner through the passages with a hand force pump of the ordinary piston or plunger type. After cleaning, flush thoroughly with clean, hot water. , (c) Clean Water Passages of Cooler. Install plugs in oil tube openings in body. Immerse body and covers in a solution composed of Ys muriatic acid and Ys water, to which has been added V 2 pound of oxalic acid to each 21/2 gallons of solu¬ tion. Remove body and covers when foaming and bubbling stops. (This usually takes from 30 to 60 seconds.) Pressure flush thoroughly with 27 TM55-1146 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 NUT AND LOCKWASHER TOP COVER DRAIN PLUG COVER GASKET BOTTOM COVER BODY COVER STUD NUT AND LOCKWASHER 36x66 REAR BEARING OIL CUP FRONT BEARING OIL HOLE (SLIDE COVER TO EXPOSE HOLE-RETURN COVER AFTER OILING) 36x15 GENERATOR OIL CUP 36x16 STARTING MOTOR GREASE CUP WICK 36x17 DISTRIBUTOR Figure 24—Oil Cooler Figure 25—Lubrication of Engine Accessories 28 TM55-1146 10-11 LUBRICATION clean, hot water. Remove all foreign substances. Clean all gasket surfaces thoroughly. (d) Flush Oil Passages. After both the oil and water passages of the cooler have been cleaned, flush inside of oil passages with clean SAE 10 engine oil. (3) Assembling. Using new gaskets, install both covers and electrode (if so equipped) and install cooler on the engine. 11. LUBRICATION OF ENGINE ACCESSORIES a. General. In order to prolong the useful life of the various accessory units of the en¬ gine, lubricate them periodically with the proper type of lubricant. Clean the fittings before lubri¬ cating and record the number of hours of engine operation between lubrications. b. Generator (fig. 25). The generator has lubrication points at the front and rear bearings. Lubricate each with a few drops of SAE 10 engine oil after each 150 hours of operation. c. Starting Motor (fig. 25). The starting mo¬ tor has an oil cup at the rear bearing. Lubricate with a few drops of SAE 10 engine oil after each 150 hours of operation. d. Distributor (fig. 25). The distributor has twOj lubrication points: a grease cup on the side of the distributor and a wick in the center of the cam. Fill the grease cup with general purpose grease No. 1 and turn the cup one complete turn each 25 hours of operation. Add two or three drops of SAE 10 engine oil to the wick each 50 hours of operation. Do not allow oil or grease to get on the distributor points, as this will cause burning of the points. 29 TM55-1146 1:2-13 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section V TROUBLE SHOOTING Paragraph’ Introduction . 12 Engine.. Fuel system. Starting system. Ignition system. Generating system. Reverse and reduction gears ...... 12. INTRODUCTION a. This section contains information which can be used to help diagnose the cause of diffi¬ culties that may arise, and lists the maintenance operation required to restore normal engine operation. Each of the symptoms given under the individual unit or system is followed by a list of possible causes. The tests necessary to determine which one may be responsible are ex¬ plained after each possible cause. b. CAUTION: Before making any electrical tests, air out the engine compartment thoroughly to remove any inflammable fumes. Sparks cre¬ ated when making electrical test connections may cause the fumes to ignite, resulting in an uncontrollable fire. 13. ENGINE a. Engine Will Not Turn. (1) Starting Motor Inoperative. See paragraph 15. (2) Incorrect Oil Viscosity. Drain and refill with proper grade of oil. (3) Seizure. Attempt to crank engine by hand. If engine will not turn, disassemble and inspect for internal damage. b. Engine Turns But Will Not Start. (1) Combustion Chamber Flooded With Fuel. Crank engine with choke off and throttle wide open. If flooding condition continues and engine will not start, check the fuel system (par. 14). (2) Fuel Does Not Reach Carburetor. Disconnect the fuel tube at the carburetor and insert the open end of the tube in a receptacle and crank the engine with the starting motor. This . 13 . 14 . 15 . 16 . 17 . 18 should cause fuel to flow from the open tube. If free flow of fuel is not evident, fuel is not reaching the carburetor. See paragraph 14. (3) Fuel Does Not Reach Cylinders. Check the choke adjustment. Hold choke valve closed and crank the engine a few revolutions with open throttle. Stop cranking and open choke; if raw fuel drains back from carburetor throat to sump in the air horn, fuel is reaching the cylinders. If fuel delivery is not evident by this test, see paragraph 14. (4) Improper Ignition. Remove wire from spark plug, hold end of the wire about )4 inch from the cylinder head and crank the engine. If spark does not jump the 14 -inch gap, the ignition is inadequate. See paragraph 16. c. Engine Misfires. (1) Improper Ignition. Clean and inspect the distributor cap, rotor and high tension cables. Inspect the breaker points; clean and adjust or replace if burned. Test the breaker arm spring tension (par. 65 h). Inspect wires and connections. With the distributor rotor re¬ moved, check for play in the drive shaft bush¬ ings; if excessive, replace the bushings. Clean and inspect the spark plugs and set the gaps to 0.025 inch. Test the ignition coil and condenser. (2) Insufficient Fuel Delivery. Inspect and clean the fuel lines and filter. Test the fuel pump (par. 22 c). Inspect carburetor (par. 14 b). (3) Valves Sticking; Valve Springs Weak or Broken. Inspect valve springs and make compression test (par. 19 c). d. Engine Does Not Develop Full Power. (1) Improper Fuel Mixture. Service the fuel filter and be sure the fuel tubes between the tank and carburetor are clear. Check the 30 TM55-1146 13 TROUBLE SHOOTING fuel pump pressure (par, 22 c) and if less than three pounds, repair or replace the fuel pump. If the fuel mixture is not corrected by this proce¬ dure, disassemble the carburetor and clean all jets and fuel passages and reset float level. (2) Intake Manifold Overheated. Flush out the manifold water jacket. On engines equipped with sea water cooling systems, close the water outlet control valve. Be sure engine compartment temperature is not excessively above normal. (3) Ignition Timing Late. Check with timing indicator and adjust the timing if neces¬ sary (par. 23 c). (4) Low Compression. Test compression (par. 19 c). (5) Valves Sticking; Valve Springs Weak or Broken. Inspect the valve springs for breakage. A manifold vacuum test will reveal sticking valves by erratic movement of the vacuum gage hand. (6) Valve Timing Incorrect. Intake valve should start to open just before the piston reaches top dead center on the exhaust stroke and the exhaust valve should be fully closed shortly after center. If the intake valve does not start to open before center or if the exhaust valve is fully closed before center, reset the cam¬ shaft timing. e. Engine Overheating (Direct Sea Water Cooling System). (1) Water Outlet Control Valve Too Far Open. Loosen lock nut on valve at front of the cylinder head and turn the valve in, to re¬ duce the amount of water recirculated. (2) Improper Circulation of Water. Make certain all drain cocks are closed. Check the flow of water at the water outlet with the engine running. If a good circulation of water is not apparent, inspect the water inlet to the pump for obstruction, collapsed hose or for broken inlet pipe or hose. If the difficulty is not located by this procedure, open the drain cock between the pump and the oil cooler and start the engine. If a good flow of water is forcibly discharged from the drain cock, indicating good pump operation, clean the water passages be¬ tween the pump and the cylinder block and flush out the oil cooler, manifold and cylinder block. If a good flow of water is not forcibly discharged from the cock between the pump and oil cooler, inspect and repair the water pump. (3) Improper Circulation of Air. Make certain that the normal circulation of air around the engine is not obstructed. f. Improper Circulation of Water (Self-con¬ tained Cooling Systems). (1) Insufficient Cooling Solution. Check level of coolant and replenish if low. (2) Contained Coolant Not Circulated. If the contained coolant does not circulate through the expansion tank with the engine running, open the drain cock at the outlet side of the engine cooling pump. If coolant is forci¬ bly discharged from the drain cock, inspect for obstruction in the system. If coolant is not forci¬ bly discharged from the drain cock, inspect the engine cooling pump. (3) Sea Water Not Circulated. Check the overflow of sea water at the outlets with the engine running. If a good circulation of water is not apparent, inspect the sea water pump in¬ let and the heat exchanger for obstruction. If the difficulty is not located by the foregoing pro¬ cedure, inspect the sea water pump. (4) Improper Circulation of Air. Make certain that the normal circulation of air around the engine is not obstructed. g. Engine Runs Too Cold (Direct Sea Water Cooling Systems). Loosen lock nut and turn the water outlet control valve adjusting screw coun¬ terclockwise, allowing enough warm water to re¬ turn to the suction side of the water pump to raise the temperature to at least 120°F. during steady operation. The water temperature should not exceed 140°F. h. Low or No Oil Pressure. (1) Oil Level Below Pump Strainer. Fill crankcase to proper level (par. 8). (2) Filter Clogged and Filter By-pass Valve Stuck. Service oil filter (par. 10). (3) Oil Leakage. Inspect for leakage at oil pipes and connections at filter, cooler, pump and cylinder block. (4) Oil Pressure Relief Valve Not Seat¬ ing. Remove and clean the relief valve (par. 33 d). 31 TM55-1146 13-14 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 (5) Oil Pump Worn or Damaged; Exces¬ sive Bearing Clearance. If causes listed in steps (1) through (4) above are not evident, in¬ spect the oil pump and pump inlet pipe and strainer. Inspect the engine bearings for exces¬ sive clearance (pars. 27 and 29). i. Excessive Oil Consumption.' (1) Oil Level Above Recom mended Level. Keep oil at proper level (par. 8 d). (2) Oil Leajkage. Inspect for oil leakage at external oil tubes, filter, crankshaft oil seals and oil pan. (3) Excessive Clearance in Engine Bear¬ ings. Inspect bearings and check clearance (pars. 34 d, 39 d (3) and 39 g). ' (4) Worn or Damaged Piston Rings or Cylinder Bores. Inspect cylinder bores and re¬ place piston rings (pars. 28 and 36). j. Excessive Fuel Consumption. (1) Flame Arrester Restricted. Remove the flame arrester from the engine. Separate the air horn from the arrester body. Wash the ele¬ ment in solvent and dry thoroughly before in¬ stalling. (2) Ignition Timing Late. Check timing and adjust if late (par. 23 c). (3) Choke Does Not Open Fully. Inspect and adjust choke (par. 22 b). (4) Fuel Level in Carburetor Too High. Check fuel level and adjust if too high (par. 43 n). (5) Carburetor Fuel Metering System Faulty. Rebuild carburetor. k. Valve Noise. (1) Valve Tappets Improperly Adjusted. Adjust tappets (par. 20). (2) Valve Spring Cocked or Broken. Aline or replace valve spring. (3) Valve Stem Gumb or Tappet Worn. Replace worn parts. l. Spark Knock or Ping. (A sharp metallic knock when operating under full load.) (1) Early Ignition Timing. Check and ad¬ just ignition timing (par. 23 c). (2) Carbon Accumulation in Combustion Chambers. Remove cylinder head and scrape carbon from cylinder head, valve and piston heads. (3) Engine Overheating. See subpara¬ graphs e or f above. m. Piston Slap. Piston slap is a clear metallic knock caused by clearance between the piston skirt and the cylinder wall. The noise may occur when the engine is operated under full load at low speed and not be heard at higher speeds or at idling speed. If piston slap is noticeable only before the engine reaches normal operating temperature, no repairs are necessary. If piston slap occurs at operating speed and normal oper¬ ating temperature, inspect cylinder bores and replace piston rings. n. Piston Pin Noise. Piston pin noise is a metallic knock, usually noticeable when idling a hot engine. The noise will come and go as the piston pin turns or shifts in the piston. Replace the piston pin. o. Bearing Noise. (1) Loose Bearing. A loose bearing is usu¬ ally heard momentarily in a series of rapid dis¬ tinct knocks when accelerating at about 2/3 maximum engine speed. It is difficult to distin¬ guish by sound between main apd connecting rod bearing noise. Inspect bearings and check the clearance. Replace bearings with excess clearance. (2) Burned-out Bearing. A burned-out connecting rod bearing will be heard as a sharp, distinct knock at most engine speeds, especially on quick acceleration. The bearing responsible for the knock can usually be determined by shorting the ignition at the spark plug. A burned-out main bearing will cause a knock at moderate speeds under load. If the rear or an intermediate bearing is responsible the knock usually can be shorted out. If in the front main bearing, the knock will have a heavy dull sound due to the additional area of that bearing. In¬ spect crankshaft journals and repair or replace shaft if damaged. Replace damaged or loose bearings. 14. FUEL SYSTEM a. Fuel in Tank Does Not Reach Carburetor. (1) Vent Hole in Fuel Tank Cap Clogged. Clear vent or replace cap. (2) Fuel Pump Filter or Lines Re. STRICTED. Service filter and blow out lines. 32 TM55-1146 14-16 TROUBLE SHOOTING (3) Fuel Pump Inoperative. If causes listed in subparagraphs (1) and (2) above are not evident, test fuel pump as follows: (a) Inspect Filter Bowl Gasket. Replace if necessary. Tighten filter bowl retainer nut. (A quick and reliable check for air leaks is to sub¬ merge the end of the fuel discharge line in gaso¬ line and check for air bubbles while cranking the engine.) (b) Inspect for Diaphragm Failure. With engine running, a leaky diaphragm will always result in gasoline leakage out of the air vent. (c) Inspect Valves. This requires disassem¬ bly of the pump. Failure of the valves is more common than failure of the diaphragm. (d) Test Fuel Delivery Rate. If pressure gage is not available, disconnect fuel line at car¬ buretor and discharge the fuel into suitable beaker or can. Crank the engine, with ignition off, and measure the fuel delivery for five revolu¬ tions of the camshaft. The number of revolu¬ tions can be counted by watching the pulsations of fuel flow. The normal delivery is 18 to 20 cubic centimeters per revolution, so the delivery should be 90 to 100 cubic centimeters (approx¬ imately Ys pint). b. Fuel Reaches Carburetor But Does Not Enter Cylinders. (1) Float Valve Stuck. Check fuel level in carburetor float bowl and if low, inspect the float valve for being stuck on the seat. (2) Carburetor Fuel Jets or Passages Clogged. If the fuel level in the float bowl is correct and no fuel is delivered to the carburetor throat, remove and disassemble the carburetor. Clean all fuel jets and passages. 15. STARTING SYSTEM a. Starting Motor Will Not Crank Engine. (1) Battery Discharged. Test the battery and if low, recharge or replace as required. (2) Loose or Corroded Battery Connec¬ tions. Clean and tighten battery cable connec¬ tions at the battery and ground and coat battery terminals with petrolatum. (3) No Current to Starting Motor Sole¬ noid Unit. Disconnect the wire which runs from the starting motor switch to the solenoid unit at the solenoid. With the ignition switch on and the starting motor switch depressed, touch the end of the wire to the starting motor housing. If spark occurs, current is being supplied to the solenoid. If no spark occurs, check the circuit through the starting motor switch, ignition switch, ammeter and back to the cable terminal on the solenoid. (4) Solenoid Unit Inoperative. Remove the cap over the end of the switch shaft and press the starting motor switch. If the switch shaft moves in when current is applied the solenoid is operative, if not see paragraph 67 d (10). (5) Starting Motor Drive Damaged. If the starting motor spins but does not crank the engine, remove and inspect the unit. (6) Starting Motor Inoperative. If the solenoid unit operates satisfactorily but the starting motor does not turn, repair or replace the starting motor. 16. IGNITION SYSTEM a. Improper Ignition. (1) Moisture on Ignition Units. Wipe dis¬ tributor cap terminals, cables, spark plugs and coil thoroughly dry with a dry cloth or a cloth saturated with carbon tetrachloride. (2) Distributor Faulty. Remove distribu¬ tor cap and rotor; inspect for cracks or carbon runners. Clean contact points and adjust or replace if burned or pitted. Examine condenser lead wire for breakage or loose connection. Crank the engine and note whether distributor shaft turns; if not, shaft may be broken; remove and repair distributor. \ (3) ' Ignition High Tension Circuit In¬ operative. Remove cable from a spark plug. With the ignition switch turned on and the en¬ gine being cranked, hold the loose end of the spark plug cable about one-quarter inch from the cylinder head. If current jumps from the cable to the cylinder head, the ignition circuit is complete through cable tested. Test other cables in the same manner. Test spark plugs in spark plug tester. (4) Ignition Primary Circuit Inopera¬ tive. If the starting motor solenoid unit operates there will be ample current in the ignition pri¬ mary circuit at least through the ignition switch. Test the primary circuit from the ignition switch to coil and distributor. Remove the dis¬ tributor cap and rotor and turn the engine until the distributor breaker points are definitely 33 TM55-1146 16-18 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 closed. Turn on the ignition switch and push the breaker points apart with the finger. If there is a slight arc of current as the points open, the primary circuit is complete and will function if the points make and break properly when the engine is cranked. If no current is indicated by making and breaking contact of the breaker points when the ignition switch is on, turn the engine until the breaker points are open and connect one lead from a voltmeter to any part of the engine that will provide a definite ground, and make the following tests: (a) Test primary wires and connections from ignition switch to the coil by connecting the other voltmeter lead to the lower left post of the coil. If battery voltage is shown, current is reaching the post. (b) Test primary circuit from coil to distrib¬ utor breaker points by moving the voltmeter lead to the lower right post of the coil and finally to the distributor breaker arm. It battery volt¬ age is shown at any of these points of test and not at the next point, the trouble will be located between these two points. (c) If very little or no voltage is shown at any point between the coil and breaker arm, dis¬ connect the condenser lead wire and connect the voltmeter lead to the breaker arm. A normal battery voltage reading then would show a shorted condenser. No voltage reading at any of the points between the coil and breaker arm with the breaker points open and the condenser lead disconnected would indicate a broken pri¬ mary circuit in the coil. 17. GENERATING SYSTEM a. Charging Rate Not Within Specifications. (1) General Inspection OF System. Test the battery and replace if necessary. Make sure the regulator is of proper type for the system and clean and tighten all wiring connections at battery, generator, regulator and ammeter. Make sure that the wiring is in good condition. (2) Generator or Regulator Faulty. Con¬ nect an accurate test ammeter in series with the battery “B” terminal at the regulator and a test voltmeter from the generator armature terminal to ground. Start the engine, increase speed grad¬ ually and observe the test meters. If voltage is shown and no amperage indicated, adjust circuit breaker cut-in voltage. If no voltage or amper¬ age reading is obtained, disconnect the field “F” lead from the generator and ground the genera¬ tor terminal. If the voltage builds up (do not exceed rated capacity of generator (par. 58 b)), the generator is satisfactory. If voltage fails to build up, repair or replace the generator. If the generator output is found to be satisfactory with the generator field terminal grounded but insuffi¬ cient charge is produced with the circuit com¬ plete, make resistance tests (subpar. (3) below). (3) High Resistance Connections. In¬ spect the wiring between the generator, regu¬ lator and battery for broken wires and high re¬ sistance connections. Pay special attention to the ground connections at all three units. Con¬ nect a reliable ammeter with one ampere gradua¬ tions in series with the regulator terminal marked “B” and the lead removed from the ter¬ minal. Run the engine and turn on lights so that the generator charges at about 10 amperes. With an accurate reading voltmeter, measure the voltage from the generator terminal marked “A” to the regulator terminal marked “A”; from the generator terminal marked “F” to the regulator terminal marked “F”; and from the regulator terminal marked “B” to the battery post. The voltage reading for any of these tests should not be more than 0.1 volt at the 10 am¬ pere charging rate. At the same charging rate, the voltmeter should show no reading when measured from the generator frame to the regu¬ lator base, from the generator frame to the bat¬ tery ground post, or to the regulator base and the battery ground post. If high voltage drop is indicated install proper size wire. If these tests are satisfactory, repair or replace the regulator. 18. REVERSE AND REDUCTION GEARS a. Engine Does Not Turn Driven Shaft Flange in Either Direction. (1) Clutch and Reverse Band Out of Adjustment. If the control lever can be moved to the limit of its travel in both directions with little effort, adjust the clutch and reverse band (par. 24). (2) Reverse Gear Assembly Damaged. If the difficulty cannot be overcome by adjustment, inspect the clutch spool assembly and the shift fork. Notice if the reduction gear pinion shaft turns with the engine turning and the control lever engaged. If the shaft does not turn, remove the reverse gear assembly (par. 30) for inspec¬ tion of parts. 34 TROUBLE SHOOTING TM55-1146 18 (3) Reduction Gear Assembly Damaged. If the reduction gear pinion shaft turns with the engine but the driven shaft flange does not turn, remove the reduction gear assembly for in¬ spection and necessary parts replacement. If the reduction gear pinion is damaged, remove the reverse gear assembly and replace the pinion. b. Engine Turns Driven Shaft Flange in For¬ ward Speed But Not in Reverse. (1) Reverse Band Out of Adjustment. Adjust the reverse band (par. 24 b). (2) Reverse Band or Drum Worn or Damaged. If the difficulty cannot be overcome by adjustment, remove the case cover and in¬ spect the reverse band and the band anchor pin. Remove the reverse gear assembly and band, if the band or drum is damaged. c. Engine Turns Driven Shaft Flange in Re¬ verse But Not in Forward Speed. (1) Clutch Out of adjustment. Adjust the clutch (par. 24 a). (2) Clutch Worn OR Damaged. If the dif¬ ficulty cannot be overcome by adjustment, re¬ move the reverse gear assembly for inspection and replacement of clutch parts. d. Engine Stalls When Reverse Band Is En¬ gaged. (1) Reverse Gear Pinions Damaged. Re¬ move the pinions for inspection. e. Noise Only While Engaging Clutch or Re¬ verse Band. (1) . Clutch Spool Bearing Worn or Dam¬ aged. Remove the reverse gear assembly and re¬ place the clutch spool assembly. f. Noise Only When Operating in Reverse. Remove the reverse gear assembly and inspect the reverse gear pinions, pinion bushings and the pinion shafts. Inspect all bushings located for¬ ward of the clutch. g. Noise When Operating in Forward Speed or Reverse. (1) Lack of Lubrication. If engine oil is not being delivered to the reverse and reduction housing, remove the assembly from the engine and inspect the oil restriction in the reverse gear oiler plug in the engine crankshaft for stoppage. (2) Misalinement Between Engine and Propeller Shaft. Separate the flanges and check the alinement (fig. 13). If misalinement is found, shift the engine as necessary to make the flanges parallel within 0.002 inch. (3) Single Reduction Gears Improperly Adjusted. Check the gear backlash and adjust the gears if necessary (par. 72 h). (4) Reduction Gears or Bearings Dam¬ aged. Remove the reduction gear assembly for inspection of parts (pars. 71 and 72). (5) Reduction Gear Pinion Bearing Dam¬ aged. Remove reduction gear assembly and in¬ spect the bearing (pars. 71 and 72). h. Reverse and Reduction Gears Over¬ heating. (1) Lack of Lubrication. If engine oil is not delivered to the reverse gear and reduction gear housing, remove the assembly and inspect the oil restriction in the reverse gear oiler plug in the engine crankshaft for stoppage. (2) Reverse Gear Cover Elbow Screen Clogged. Remove and clean screen. % (3) Clutch or Reverse Band Slipping. If heating occurs in forward speed, adjust clutch (par. 24 a). If heating occurs in reverse, adjust the reverse band (par. 24 b). If adjustment does not overcome the slippage, remove the reverse gear assembly for inspection. i 35 TM55-1146 19 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section VI TESTS AND ADJUSTMENTS Paragraph . 19 . 20 . 21 . 22 . 23 . 24 Vacuum and compression tests Valve tappet adjustment Battery service Fuel system tests and adjustments Ignition system tests and adjustments Reverse gear adjustments 19. VACUUM AND COMPRESSION TESTS a. General. To maintain operating efficiency, keep the units of the ignition and fuel systems in proper adjustment. Vacuum and compression tests will reveal the operating condition of the engine and indicate the need for engine tune-up or replacement of internal parts. b. Vacuum Test (fig. 28). (1) General. Vacuum readings are affected by: (a) Improper carburetor adjustment. (b) Improper ignition timing. (c) Burned, riding or sticking valves. (d) Loose valve guides; weak valve springs. (e) Leaky intake manifold or carburetor gaskets. (f) Poor piston ring seal. (2) Procedure. Run the engine until normal temperature is reached. Attach the vacuum gage hose to the intake manifold just above the car¬ buretor and note the reading on the gage. An engine in perfect condition, running at idle speed, should show a reading of 18 to 21 inches of vacuum with the gage hand steady. c. Compression Test. (1) General. Normal and uniform com¬ pression is essential for efficient engine oper¬ ation. A compression pressure test is affected by engine cranking speeds, engine temperatures, compression ratios, condition of valves and pis¬ ton rings as well as the amount of carbon deposit in the combustion chambers. (2) Procedure (fig. 26). Run the engine until normal operating temperature is reached. Remove all spark plugs and install the compres¬ sion gage in the spark plug hole of one cylinder. With the throttle wide open, crank the engine at least 125 revolutions per minute with the starter until maximum pressure is registered on the gage. Record the reading and repeat the test on the remainder of the cylinders. (3) Interpretation of Gage Readings. If the reading on the gage is reasonably high (90 to 110 pounds) and not varying more than 10 pounds between cylinders, the compression pres¬ sure can be considered normal. If the pressure of any cylinder is weak, inject oil through the spark plug hole onto the top of the piston with the pis¬ ton down. Wait a few minutes for the oil to run down over the piston rings and so it will not get on the valves, then repeat the test. The oil will seal the rings so that after making a second test, if the reading is still low, leaking valves are indi¬ cated. A low reading on the first test which, after oil injection, becomes a high reading, indicates leaky rings. If either condition exists, grind the 36x18 Figure 26—Compression Test 36 TESTS AND ADJUSTMENTS TM55-1146 19-22 valves or replace piston rings. An extremely low reading between two adjacent cylinders indi¬ cates a leaky cylinder head gasket. 20. VALVE TAPPET ADJUSTMENT a. The intake valve tappet clearance is 0.010 inch (engine hot or cold) ; the exhaust valve tap¬ pet clearance is 0»014 inch (engine cold) or 0.012 inch (engine hot). If accessible, check the valve tappets for proper clearance as follows: (1) Remove the valve spring covers and crank the engine until tappet rests on the back of the cam. (2) Insert a feeler gage between the bottom of the valve stem and the adjusting screw (fig. 27). Hold the tappet from turning with a wrench and adjust the screw until a slight drag is felt on the feeler gage. (3) Install the valve spring covers, using good gaskets. TAPPET ADJUSTING SCREW VALVE TAPPET FEELER GAGE 36x19 Figure 27—Valve Tappet Adjustment 21. BATTERY SERVICE a. Inspection. Inspect the battery after each 50 hours of operation. Add distilled water, or water that is suitable for drinking, to keep the electrolyte level (battery fluid) % inch above the top of the battery plates. Clean the battery cable terminals and battery posts frequently. b. Voltage Test. Test each battery cell sep¬ arately. Press the prods of the voltage tester firmly agaipst the negative and positive posts of the cell. The voltmeter should read 1.9 to 2.2 volts for each cell in the battery. c. Hydrometer Test. Remove the battery filler caps and test the electrolyte solution with a hydrometer. The charge in the battery will be indicated by the figure on the small tube which shows just above the level of the solution. Add to or subtract from the reading in accordance with the temperature scale on the hydrometer to obtain the actual specific gravity. The following hydrometer readings show the charged condi¬ tion of the battery at normal operating tempera¬ ture (80°F.) : Fully charged..1.275 to 1.300 Half charged.1.225 Very low.1.150 If the battery is less than half charged, recharge or replace with a fully charged battery. d. Temperature at Which Battery Will Freeze. A fully charged battery will not freeze in temperatures where the engine will be oj^er- ated, but a battery with 1.120 specific gravity will freeze at 14°F, above zero. Following are the freezing temperatures of the battery for various specific gravity readings: Specific Gravity Freezing Temperatures 1.160.+1.5° F. 1.200.—17°F. 1.240.—50°F. 1.280..—96° F. e. Specific Gravity for Hot Climates. In hot climates (95°F. and above) lower specific grav¬ ity electrolyte is recommended to avoid excessive deterioration of plates and separators. To lower the specific gravity of a fully charged battery, remove the electrolyte to the level of the plates. Add distilled water, or water that is suitable for drinking, to bring the battery fluid up to % inch above the plates. Charge the battery until a spe¬ cific gravity of 1.245 is obtained. Refer to para¬ graph 60 b (5) for voltage regulator setting. 22. FUEL SYSTEM TESTS AND ADJUSTMENTS a. Carburetor Adjustments. (1) Adjust Fuel Mixture (fig. 28). (a) Make Initial Setting of Adjusting Screw. Close the idle mixture adjusting screw and the high speed adjusting screw. Then back the screw out one full turn. Use fingers only to turn the screw as more pressure will damage the valve and valve seat. 37 TM55-1146 22-23 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 (b) Adjust High Speed Mixture. Start the engine and turn high speed adjusting screw in the direction required to develop the best per¬ formance at intermediate and high speeds. (c) Adjusting Idling Mixture. Connect a vacuum gage in the intake manifold above the carburetor. Turn the idle mixture adjusting screw in the direction required until the vacuum gage shows the highest reading with a steady hand. (2) Adjust Engine Idling Speed. Adjust the throttle stop screw in or out until the engine runs at approximately 500 revolutions per min¬ ute. b. Choke Adjustment. Disconnect the choke pull rod from the choke shaft lever. Push the choke button all the way in, then pull it out about inch. Hold the choke valve open against the stop and connect the choke pull rod to the lever. Adjust choke so that it closes fully when button is pulled all the way out. THROTTLE IDLE IDLE MIXTURE VACUUM ADJUSTING SCREW ADJUSTING SCREW GAGE Figure 28—Carburetor Adjustments c. Fuel Pump Test. Install a pressure gage between the fuel pump and, the carburetor and run the engine. If the pressure is 3 to 4 V 2 pounds, the pump is operating satisfactorily. If the pres¬ sure shown on the gage is less than three pounds, inspect the tube between the pump and supply tank. If the tube is clear and the connections tight, repair or replace the fuel pump. 23. IGNITION SYSTEM TESTS AND ADJUSTMENTS a. Breaker Points. Examine the breaker points for corrosion or pitting. If either condi¬ tion exists, dress the points down to insure a clean square contact or install new points. Rotate the distributor shaft until the breaker point rub¬ bing block is on a high point of the cam and adjust the breaker point gap to 0.020 inch. b. Spark Plugs. Remove and clean the spark plugs. Clean and inspect the porcelain for cracks. Set the gap to 0.025 inch, using a round feeler gage. Make the adjustment on the side wire. If the center wire is bent, the porcelain may crack, resulting in plug failure. Install the spark plugs and tighten them with a torque wrench to 26 to 32 foot pounds. c. Adjust Ignition Timing (fig. 29). Remove the timing plug over number one cylinder and install a timing indicator in the hole. (Number one cylinder is at the flywheel end of the engine.) Turn the engine slowly until number one piston is coming up on the compression stroke and stop when the piston is two degrees or 0.002 inch be¬ fore top dead center. Loosen the distributor ad¬ justing arm lock screw and rotate the distributor body until the points just start to open. This may be checked by disconnecting the primary lead from the distributor and connecting a test lamp between the distributor terminal and the battery terminal of the generator regulator. When the points are closed, the light will be on, and as soon as the points break the light will go out. Press the distributor cam lightly against the direction of Figure 29—Ignition Timing Adjustments 38 TESTS AND ADJUSTMENTS TM55-1146 23-24 0.006 TO 0.010-INCH CLEARANCE’ OPERATING LEVER SET SCREW BACK PLATE CLUTCH BACK PLATE LOCK 36x22 Figure 30—Clutch and Reverse Band Adjustment proper rotation to remove all backlash. When engine is operating under full load, adjust timing of distributor to just eliminate ping. 24. REVERSE GEAR ADJUSTMENTS a. Clutch Adjustment (fig. 30). Slippage of the forward clutch causes unnecessary wear on the clutch friction surfaces. Adjustment should be made if the control lever does not snap into place when put into the forward position, or if it becomes necessary to hold the control lever in the forward position. Continued forward pressure on the clutch control lever causes unnecessary wear of the thrust bearing. If the craft is built with remote control for the clutch, see that the connecting linkage is free in its action at all times and has a minimum of lost motion. To ad¬ just the clutch, remove the cover from the reverse gear case and remove the back plate lock on the back of the clutch drum back plate. To tighten the clutch, hold the clutch drum stationary (hold clutch lever in reverse position) and rotate the clutch drum back plate to the right (clockwise). Two notches are usually required. To loosen the clutch, rotate the drum back plate counterclock¬ wise. Install back plate lock and try clutch for “gripping”; readjust if necessary. b. Reverse Band Adjustment (fig. 30). Move the control lever to the reverse position. Adjust the reverse gear band operating lever set screw until the clearance between the reverse gear band operating lever tappet nut and the lever is Vir. to %4 inch, then tighten the set screw lock nut. Adjust the reverse gear band adjusting rod until the clearance between the nut and the adjusting rod guide is 0.006 to 0.010 inch. Hold the adjust¬ ing nut and tighten the lock nut. 39 TM55-1146 25-27 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section VII REPAIR OPERATIONS Cylinder head and gasket. Valves and springs. Connecting rod bearings. * Pistons, pins and rings. Crankshaft bearings. Reverse and reduction gear assembly 25. CYLINDER HEAD AND GASKET a. Removal. Remove the spark plugs and spark plug cable assembly. Remove the water outlet pipe and the water pipe from the oil cooler to the manifold. Disconnect the small manifold ventilator pipe between the manifold and the front of the cylinder head and remove the elbow from the manifold. Disconnect the ignition coil from the cylinder head. Remove the cylinder head stud nuts and lift off the head and gasket. b. Cleaning and Inspection. See paragraphs 32 a, 33 a and b. c. Installation. Place the gasket and cylinder head in position and install the stud nuts. Then starting with the center nut, tighten them with a torque wrench to 55 to 60 foot pounds in the se¬ quence shown in figure 51. Install the elbow and connect the small manifold ventilator pipe be¬ tween the cylinder head and the manifold. In¬ stall the water outlet pipe and the water pipe be¬ tween the oil cooler and the manifold. Install the spark plugs and the spark plug cable assembly. Install the ignition coil on the cylinder head. Re¬ tighten cylinder head stud nuts to 55 to 60 foot pounds, with engine hot. 26. VALVES AND SPRINGS a. Removal. (1) Remove Cylinder Head. See paragraph 25 a. (2) Remove Valves. Remove the valve spring covers and gaskets. Turn the engine until valve is all the way down (closed). Raise the valve spring with a valve spring lifter and take out the valve locks and valve (fig. 31). Remove the lifter and take out the valve spring and re¬ tainer. If more than one valve is to be removed, place them in position so that they can be identi¬ fied for installation in the same port from which they were removed. Paragraph . 25 . 26 . 27 . 28 . 29 . 30 b. Cleaning and Inspection. See paragraph 35 c through f. c. Installation. (1) Install Valves and Adjust Tappets. Place the valve springs in position with the close¬ ly coiled end of the spring up and the spring re¬ tainer in the lower end of the spring. Lubricate the valve stems and install each valve in its proper port. Use a valve spring compressing tool and compress the spring and install the valve locks. Adjust the intake tappets to 0.010 inch and exhaust tappets to 0.014 inch. Install the valve spring covers and gaskets. (2) Install Cylinder Head and Gasket. See paragraph 25 c. 27. CONNECTING ROD BEARINGS a. Removal. (1) Remove Oil Pan. Remove the engine oil. Remove the lower cap screws which attach the reverse gear case to the timing gear case. These cap screws run through the timing gear case and enter the end of the oil pan. Remove all cap screws from the oil pan flange and lower the pan and gasket from the block. (2) Remove Connecting. Rod Bearings. Remove the rod bolt nuts, the bearing caps and lower bearing inserts. Push the connecting rod and piston assemblies up slightly and remove the upper inserts. b. Inspection. If the bearing inserts are scored, cracked or burned, replace both upper and lower halves. Inspect the crankshaft jour¬ nals and if damaged or out-of-round or tapered more than 0.001 inch or wear on the diameter exceeds 0.002 inch, install a reground or new crankshaft. 40 REPAIR OPERATIONS TM55-1146 27-29 c. Installation. (1) Install Connecting Rod Bearings. Clean the mating surfaces of the rods and in¬ serts. ^Place the bearing inserts in the connecting rod and bearing cap. Make sure the tongue in the bearing inserts lines up with grooves in rod and cap. Pull the rod onto the shaft and install the bearing cap with special lock washers. Tighten the connecting rod bolt nuts to 45 to 50 foot pounds with a torque wrench. Install the oil strainer. (2) Install Oil Pan (fig, 48). Coat the gasket recess in the front end of the oil pan and the flange with sealing compound and install a new end gasket so that the ends stick up an equal distance above the flange. Do not cut the ends off as they will compress when the pan is in¬ stalled. Place new gaskets on the flange and over the ends of the end gasket. Raise the pan into position, being careful not to damage the gasket on the timing gear case. Install and tighten the oil pan flange cap screws before installing the long cap screws through the timing gear case. Fill the oil pan to the correct level with the rec¬ ommended grade of engine oil. 28. PISTONS, PINS AND RINGS a. Removal. (1) Remove Cylinder Head. See paragraph 25 a. (2) Remove Piston and Connecting Rod Assembly. Remove the oil pan and gasket (par. 27 a (1) ). Remove the oil strainer assembly. Re¬ move any ridge that may have formed on the cylinder wall at the top of the piston ring travel, being careful not to cut more than Vm inch below the bottom edge of the ridge. Remove the con¬ necting rod bearing cap. Push the piston and connecting rod assembly out through the top of the cylinder bore. b. Cleaning and Inspection. See paragraph 36. c. Installation. (1) Install Piston and Connecting Rod Assembly. Wipe the assembly thoroughly clean and coat the piston and rings with oil. Space the rings on the piston so that the gaps on the adjacent rings are on opposite sides of the piston but do not line up with the gap of any other ring. Compress the piston rings with a ring compress¬ ing tool and insert the assembly through the top of the cylinder bore with the oil hole in the lower end of the connecting rod bearing toward the valve side of the engine, if the engine runs clock¬ wise (standard rotation) when viewed from the rear (reverse gear) end of the engine. See figure 46. Install the assemblies with the oil holes away from the valves if the engine runs in opposite rotation. Place the upper bearing insert in the connecting rod with the tongue in insert matched with the groove in the rod and pull the rod onto the journal. Install the lower insert and bearing cap with special lock washers. Tighten the bolt nuts to 45 to 50 foot pounds with a torque wrench and install the oil strainer. (2) Install Oil Pan and Oil. See para¬ graph 27 c (2). 29. CRANKSHAFT BEARINGS a. Removal. (1) Remove Oil Pan. See paragraph 27 a ( 1 ). (2) Remove Crankshaft Bearings. Re¬ move oil strainer and oil inlet pipe. Prick-punch all bearing caps so that they may be installed in their original positions. Remove the bearing cap screws and one bearing cap at a time. Remove the bearing from the cap and rotate the crank¬ shaft to remove the upper bearing from the cyl¬ inder block. Remove the lower half of the front crankshaft bearing oil seal and retainer from the bearing cap. b. Inspection. See paragraph 34 d. c. Installation. (1) Install Crankshaft Bearings. At¬ tach the lower half of the front main bearing oil seal and retainer to the machined surface of the bearing cap. Clean the crankshaft bearing bore and the upper half of the bearing inserts and in¬ stall the inserts in the bore. Make sure that the tongue in the bearing insert lines up with the groove in the cylinder block. Clean the bearing caps and inserts and install the inserts in the caps. Make sure the tongue in the bearing insert lines up with the groove in bearing cap. Select the caps according to the punch marks and install all but one cap. (2) Measure Clearance and Install Caps AND Seals. To insure the proper fit of the bear¬ ings, place a one-inch strip of 0.002 inch brass 41 TM55-1146 29-30 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 shim stock, 1/2 inch wide, lengthwise between the remaining bearing cap insert and journal and install the screws. See figure 45. Tighten the screws to 75 to 80 foot pounds with a torque wrench. A drag will be felt when turning the shaft by hand if the clearance is correct. If no drag is felt, try the next undersize bearing. Re¬ move bearing cap and feeler stock and follow the same procedure to fit the rest of the bearings. Before finally installing the front bearing cap, install the new seals on each side of the cap and cement the gaskets to the top surface of the cap. When installing the cap, see that the seals remain in position. After each bearing has been fitted individually, tighten all cap screws to 75 to 80 foot pounds with a forque wrench. (3) Install Oil Strainer and Oil Pan. Install the inlet oil pipe with the open end toward the right side of the engine. Install oil strainer with stop lug on each side of the stop on inlet tube and with strainer to the center of the en¬ gine. Install the oil pan and oil (par. 27 c (2)). . 30. REVERSE AND REDUCTION GEAR ASSEMBLY a. Removal. Remove the cap screws which attach the reverse gear case to the timing gear case and move the assembly away from the en¬ gine. b. Disassembly, Inspection and Assembly. See paragraphs 71 and 72. c. Installation. Suspend the reverse and re¬ duction gear assembly on a hoist so that it can be rocked slightly to engage the pinion gears with the crankshaft gear. Hold the mounting flange parallel and centered with the flange of the tim¬ ing gear case and move the assembly into place over the bushings. Install the mounting cap screws. Strike the starting jaw on the front of the crankshaft with a soft hammer to relieve any end thrust that may have been imposed on the shaft by the installation of the reduction gear assembly. Measure the backlash between pinion and internal reduction gear (par. 72 h). 42 TM55-1146 31 DISASSEMBLY OF ENGINE Section VIII DISASSEMBLY OF ENGINE Disassembly of engine (engine removed) * 31. DISASSEMBLY OF ENGINE (ENGINE REMOVED) a. Remove Carburetor. Remove the air si¬ lencer and flame arrester assembly and the sup¬ port arm. Disconnect the flexible fuel line from the carburetor. Remove the stud nuts which hold the carburetor to the manifold and then remove the carburetor. b. Remove Fuel Pump. Disconnect the fuel tube from the fuel pump. Remove the attaching cap screws and lift off the fuel pump, c. Remove Oil Filters and Oil Cooler. (1) Remove Full-flow Strainer Type Oil Filter. Disconnect the oil pipes leading from the oil pump to the oil cooler. Remove the attaching cap screws and the filter assembly. (2) Remove By-pass Absorption Type Oil Filter. Remove the oil pipes from the oil filter to cylinder block. Remove the attaching cap screws and the filter assembly. (3) Remove Full-flow Absorption Type Oil Filter. Disconnect the oil pipes leading from the oil pump to the oil cooler. Remove the attach¬ ing cap screws and the filter assembly. (4) Remove Oil Cooler. Disconnect the oil and water pipes from the oil cooler. Remove the attaching cap screws and the cooler assembly. d. Remove External Oil and Water Pipes. Remove external oil and water pipes from the water pump, cylinder block and head and the manifold. e. Remove Manifold and Cylinder Head. (1) Remove Manifold Assembly. Discon¬ nect the water tube and the small manifold vent tube from the manifold and cylinder head. Re¬ move the attaching stud nuts and lift the mani¬ fold assembly off the studs. (2) Remove Cylinder Head. Remove the ignition coil, spark plug cable assembly and dis¬ tributor cap. Remove the spark plugs and cylin- Paragraph . 31 der head stud nuts. Lift the cylinder head and gasket off the studs. f. Remove Distributor and Starting Motor. Remove the distributor adjusting arm lock screw and pull out the assembly. Remove the mounting cap screws and pull the starting motor from the flywheel housing. g. Remove Generator and Water Pump. Re¬ move the three mounting stud nuts and pull the generator out of the timing gear case. Remove the mounting cap screws and the water pump from the timing gear case. h. Remove Oil Pump and Oil Pressure Relief Valve. Remove the mounting cap screws, with Yn\ alien-type wrench, and pull the oil pump as¬ sembly from the cylinder block. Remove the hexagon plug and the oil pressure relief valve as¬ sembly from the cylinder block. i. Remove Reverse and Reduction Gear As¬ sembly. Remove all cap screws which hold the reduction gear housing to the timing gear case and move the assembly off the gear and bearing. j. Remove Oil Pan and Mount Engine in Stand. Remove the attaching cap screws and the oil pan. Place the engine in a suitable engine stand and clamp it securely by the lower oil pan flange. k. Remove Flywheel and Housing. Remove the nuts from the flywheel attaching bolts. Drift the bolts back as far as possible and remove the starting jaw. Remove the cap screws which hold the flywheel housing to the cylinder block and with a soft hammer, tap the housing off the dowel pins and the flywheel off the crankshaft flange. l. Remove Valves, Springs, Retainers and Locks (fig. 31) . Remove the valve spring covers. Turn the engine until a valve is all the way down, then raise the valve spring with the valve spring lifter and remove the valve locks. Remove the lifter and take out the valve, valve spring and retainer. Remove the rest of the valves in the same manner. Place the valves in position so that 43 VALVE TM55-1146 31 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 which hold the tachometer drive gear and the camshaft gear to the camshaft. Remove the tachometer gear and, through the opening for the generator, tap the camshaft gear from the shaft and remove the gear through the opening in the top of the case. Remove the attaching cap screws and tap the timing gear case off the dowel pins. o. Remove Piston and Connecting Rod As¬ semblies. Remove any ridge that may have formed on the cylinder wall at the top of the pis¬ ton ring travel with a ridge reamer. Do not cut more than %4 inch below the bottom edge of the ridge. Remove the oil strainer assembly from the oil pump inlet pipe and unscrew the pipe from the cylinder block. Remove the connecting rod bolt nuts, bearing caps and bearings. Push the piston and connecting rod assemblies out through the top of the cylinder bores. p. Remove Crankshaft and Bearings. Prick- punch all bearing caps so that they may be in¬ stalled in their original positions. Remove the bearing cap screws, and bearing caps. Lift the crankshaft out of the block and remove the bear¬ ing inserts from the block and caps. Remove the lower half of the front main bearing oil seal re¬ tainer from the bearing cap. Remove the upper half of the oil seal retainer from l^he cylinder block. Remove the crankshaft gears with an ar¬ bor press. Press against the end of the crank¬ shaft, not against the oil metering plug. q. Measure Camshaft Bearing Clearance (fig. 33). Attach a dial indicator to the block with the plunger of the indicator resting on the Figure 33—Measuring Camshaft Bearing Clearance they can be identified for installation in the same port from which they were removed. Figure 31—Removing Valve Locks m. Check Timing Gear Backlash (fig. 32). Remove the small plate from the top of the tim¬ ing gear case and attach a dial indicator with the plunger against a tooth of the camshaft gear. Rock the camshaft gear in the crankshaft gear and note the amount of backlash shown by the indicator. If the backlash exceeds 0.015 inch, replace the timing gears. CAMSHAFT TIMING GEAR Figure 32—Measuring Timing Gear Backlash n. Remove Timing Gear Case and Gears. Re¬ move the tachometer pinion housing and pinion from the timing gear case. Replace the pinion if worn or damaged. Remove the cap screws DIAL INDICATOR VALVE LIFTER VALVE SPRING RETAINER LOCKS 36x23 CRANKSHAFT TIMING GEAk 44 TM55-1146 31 DISASSEMBLY OF ENGINE back of the cam nearest a bearing. Pry the shaft to and from the indicator so that the movement will be shown on the indicator. Check all bear¬ ings in the same manner. If the clearance ex¬ ceeds 0.004 inch, remove cap screws which hold the camshaft thrust plate to the cylinder block. Turn the camshaft one revolution to force the tappets away from the cams and carefully with¬ draw the camshaft. Lift the tappets out of the block and identify them so they can be installed in the guides from which they are removed. In¬ stall a new camshaft and \echeck the clearance. If the clearance, with a new camshaft, exceeds 0.004 inch, replace the camshaft bearings. r. Remove Camshaft Bearings. If the cam¬ shaft bearings are to be replaced, use a suitable pulling fixture and remove the bearings, being careful not to burr or damage the bores in the block. Any damage to the bores will interfere with the installation of new bearings. 45 TM55-n46 32-33 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section IX INSPECTION AND REPAIR OF ENGINE PARTS Paragraph . 32 34 35 36 37 38 Cleaning of parts. Cylinder block and head. Crankshaft and bearings.. Camshaft, valves, springs and tappets Connecting rod and piston assembly. . Intake and exhaust manifolds. Oil pan, strainer, filters and cooler.... 32. CLEANING OF PARTS a. General. After the engine has been com¬ pletely disassembled, clean each part thoroughly to remove all traces of oil, grease and carbon. Remove all traces of gasket or sealing compound by scraping and washing in a suitable solvent. As soon as each part is thoroughly cleaned, in¬ spect it for flaws, score marks or indications of excessive wear and if it is to be used for reassem¬ bly keep it covered to protect it from dust and dirt. (1) Aluminum Parts. Soak all aluminum alloy parts in dry-cleaning solvent. Rinse the parts in hot water and dry thoroughly. Never, under any circumstances, immerse aluminum or aluminum alloy parts in a steel stripping solu¬ tion, regardless of how weak the solution may be. (2) Steel and Iron Parts. Immerse steel and iron parts in a suitable cleaning solution long enough to dissolve all grease and dirt. Remove parts and rinse off with hot water. Blow out with compressed air and wipe dry. (3) Oil Lines and Passages. Remove the necessary plugs in order that all oil lines and passages in the crankcase may be thoroughly cleaned by forcing steam through them until the steam flows through unrestricted. 33. CYLINDER BLOCK AND HEAD a. Inspect Castings. Clean and inspect all parts of the castings thoroughly for cracks or warpage. If a crack is found other than in the cylinder bore or valve seat, repair by welding if accessible or replace the part. If a crack is found in the cylinder bore or valve seat, replace the cylinder block. b. Inspect Gasket Surfaces. Use a steel straightedge on the machined surfaces of the block and head to determine whether they are true. If the surface is warped or irregular to the extent that a 0.010-inch feeler gage can be passed between the straightedge and the ma¬ chined surface, resurface the part or replace it. Do not remove more metal than is necessary as this will affect compression ratio. Remove the timing gear oil tube and clean thoroughly. c. Inspect Oil Pressure Relief Valve (fig. 34). Remove lock wire, unscrew the ad/usting screw and remove the spring and plunger. Clean all parts in dry-cleaning solvent, making sure that all passages are open and clean. Examine all parts for score marks or fracture and replace if necessary. Install plunger, flat end first, and place plunger spring in position. Then install new gasket and original cap. PLUNGER SPRING GASKET CAP 35x7 Figure 34—Oil Pressure Relief Valve Disassembled 46 INSPECTION AND REPAIR OF ENGINE PARTS TM55-1146 33-35 d. Inspect and Replace Core Hole Plugs. If leakage at a core hole plug is apparent, drive a center punch or similar tool through the center of the plug and remove the plug. Clean the plug seat thoroughly and remove any irregularities from the new plug. Coat the edge of the new plug with white lead and place the plug in the core hole with the concave surface facing in¬ ward. Expand the plug tight in the hole by strik¬ ing it in the center with a blunt tool. e. Inspect and Repair Cylinder Bores (fig. 35). Measure the taper and the out-of-round of the cylinder bores with a cylinder gage. If the bore is out-of-round more than 0.002 inch, tap¬ ered more than 0.0025 inch, or scored, recondition the bore for an oversize piston (par. 36 d and f). Bore to within 0.001 inch of the finished size, then hone to a smooth, bright finish to insure sat¬ isfactory ring life. Figure 35—Measuring Cylinder Bore 34. CRANKSHAFT AND BEARINGS a. Clean Oil Passages in Shaft. Remove the reverse gear oiler plug from the rear of the shaft and thoroughly clean the oil passages in the shaft and plug. b. Inspect Bearing Journals. Inspect the crankshaft and connecting rod bearing journals for scores or damage and measure the diameter, taper and out-of-round with a micrometer. If any of the journals are out-of-round or tapered more than 0.001 inch or wear on the diameter exceeds 0.002 inch, regrind the journals for un¬ dersize bearings. When grinding the journals. maintain bearing fillets with a true radius of %2 to %2 inch. Run-out should not exceed 0.002 inch. c. Check End Play (fig. 36). Install new front and rear bearing inserts in the block. Place the crankshaft in the block and install the front bearing cap with a new bearing insert. Tighten the bearing cap screws to 75 to 80 foot pounds. Pry the shaft toward the rear (timing gear case end) of the engine and measure the clear¬ ance between the end of the bearing insert and the thrust surface of the shaft. If the clearance exceeds 0.010 inch, replace the crankshaft. 35x8 Figure 36—Measuring Crankshaft End Play d. Inspect Bearings. Examine the crankshaft (main) bearings and connecting rod bearings and if found to be cracked, chipped or damaged in any way, replace the bearings. Crankshaft (main) bearings are available in standard size and under¬ sizes of 0.001 and 0.002 inch. Connecting rod bearings are available in standard size and under¬ sizes of 0.001 and 0.002 inch. Always replace bearings in pairs. 35. CAMSHAFT, VALVES, SPRINGS AND TAPPETS a. Inspect Camshaft (fig. 37). Examine the camshaft lobes and the distributor and oil pump drive gear for excessive wear or damage. Re¬ place shaft if damaged. Insert a feeler gage be¬ tween the thrust plate and the rear bearing jour¬ nal and measure the camshaft end play. The standard clearance is 0.002 to 0.006 inch. If the clearance is greater than 0.010 inch, replace the thrust plate, gear hub or both. b. Inspect Tappets (fig. 38). Clean and dry the tappets and guides and insert the tappet in 47 TM55-1146 35 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Figure 37—Measuring Camshaft End Play its guide. Attach a dial indicator to a valve spring cover stud. Raise the tappet slightly above the lower end of its normal travel and place the dial indicator plunger against the upper end of the tappet. Move the tappet in and out against the plunger (crosswise of the engine) and note the tappet clearance indicated on the dial. If the clearance is greater than 0.002 inch, ream the cylinder block opening and install a 0.001-, 0.008- or 0.030-inch oversize tappet. If the top'of the tappet screws are worn unevenly, grind the sur¬ face of the screw flat and smooth. c. Clean, Inspect and Reface Valves. If valve is cracked, warped or burned excessively, replace the valve. Measure the valve stem in several places with a micrometer. The standard measure¬ ment is 0.340 to 0.341 inch for the intake valve stem and 0.3385 to 0.3395 inch for the exhaust valve stem. If the stem is worn more than 0.002 inch, replace the valve. If the stem is worn ex¬ cessively uneven, indicating that the valve spring is not seating properly, replace the spring. Re¬ face the valves. Set the valve refacer at an angle of 45 degrees and dress the abrasive wheel so that it is smooth and true. Install the valve in the chuck and grind the face smooth.' Remove only enough metal to give a smooth regular surface. If the head of the valve is warped, replace it. d. Clean and Inspect Valve Stem Guides (fig. 39). Clean the interior of the valve stem guide with a wire brush and dry-cleaning solvent. Place the valve in the guide with the head of the valve %6 inch above the cylinder block. Attach a dial indicator to a convenient stud in the cylinder block and adjust the plunger of the indicator against the edge of the valve head. Hold the valve so it will not turn and move it toward and away from the indicator and note the amount of play shown on the dial. The clearance between the valve stem and guide will be one-half the amount shown on the indicator. The amount of wear in the guide,>would be the clearance above standard less the wear on the valve stem. If an intake valve stem guide is worn to give morb than 0.005 inch clearance, or an exhaust valve stem guide is worn to give more than 0.007 inch clearance, replace the guide. ( 1) Remove Valve Stem Guides. Drive the valve stem guides down with a special drift and break off the exposed lower section of the guide, then drift the rest of the guide from the cylinder block. DIAL INDICATOR 32X84 Z^x27 DIAL INDICATOR Figure 38—Measuring Valve Tappet Clearance ♦ Figure 39—Measuring Valve Stem Clearance 48 INSPECTION AND REPAIR OF ENGINE PARTS TM55-1146 35-36 (2) Install Valve Stem Guides. Clean the exterior of the valve stem guides and the guide hole in the cylinder block thoroughly. Start the guide in the hole with the tapered end up. Use a drift to drive the guide down into place. The tops of the valve guides must be % inch below the head surface of the cylinder block. Ream the guides with an expansion reamer to 0.3425 to 0.3435 inch. If a valve with a slightly worn stem is to be installed, reduce these dimensions the amount that the stem is worn. e. Inspect Valve Seats. If the intake valve seat is cracked or badly damaged, replace the cyl¬ inder block. If examination reveals that the ex¬ haust valve seat inserts are cracked, damaged or loose in the cylinder block, install a new 0.010 inch oversize insert. b. Inspect Piston and Pin (fig. 41). Examine piston carefully; if found to be scored, cracked, or otherwise damaged, replace the piston. Use new rings and check the side clearance of the rings in the piston. If the side clearance exceeds the maximum allowable of 0.008 inch for the compression rings or 0.004 inch for the oil rings, replace the piston. Measure the diameter of the piston pin with a micrometer and if the diameter is less than 0.8591 inch, replace the pin. Piston pins are available in standard size and oversizes of 0.003 and 0.008 inch. c. Inspect Connecting Rod. Inspect the bush¬ ing in the pin end of the connecting rod and if found to be cracked or badly worn, replace the bushing. Check the connecting rod for twist or bend in a suitable fixture. The maximum allow- (1) Replace Exhaust Valve Seat Inserts. Remove the valve seat insert. Cut the counter¬ bore 0.0035 inch smaller than the insert that is to be installed, with valve seat insert cutting tool. Run the cutter down until it bottoms in the orig¬ inal counterbore. Clean cuttings from the coun¬ terbore and valve port. Chill the insert with dry ice and use a special drift to install the insert in the cylinder block. (2) Grind Valve Seats. Clean the valve guides thoroughly. Use the correct size stone with an angle of 45 degrees and grind just enough to form a smooth seat Me to %2 inch wide. If the seat is excessively wide, use a 20-degree stone to reduce the width. Use a dial indicator to check the run-out which must not exceed 0.001 inch. Clean away all traces of abrasives after grinding the seat. f. Inspect and Test Valve Springs. Clean the spring thoroughly in dry-cleaning solvent and examine carefully. If the metal is rusted or etched, replace all springs. Test the spring for proper tension with a valve spring tester. See paragraph 2 i for specifications. Replace any spring that compresses with less than the speci¬ fied tension, as a weak spring will cause ineffi¬ cient engine operation. 36. CONNECTING ROD AND PISTON ASSEMBLY a. Disassemble Connecting Rod and Piston Assembly (fig. 40). Remove the piston pin. Re¬ move piston rings and thoroughly clean all traces of carbon from the ring grooves and oil holes. CAP BOLTS OIL HOLES PISTON PIN BUSHING CONNECTING ROD TONGUE AND GROOVE ROD BEARINGS PISTON PIN LOCK WIRE PISTON OIL HOLE PISTON RING- INTERMEDIATE PISTON RING-UPPER PISTON RINGS-LOWER PISTON PIN PISTON PIN LOCK WIRE CAP BOLT NUT LOCK WASHERS CAP BOLT NUTS CAP 35 X 59 Figure 40—Connecting Rod and Piston Disassembled 49 TM55-n46 36-37 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 35x60 Figure 41—Measuring Piston Ring Side Clearance able twist or bend is 0.0025 inch. If necessary, straighten the rod in a straightening press. d. Fit Pistons to Cylinder Bore (fig. 42). If the pistons are to be replaced, select new pistons that will just slide slowly through the cylinder bore under their own weight. If the cylinders have been rebored, be sure the cylinder bore and piston is clean and dry, then place the piston up¬ side down in the cylinder bore with a strip of 0.002-inch feeler stock, V 2 inch wide and approx¬ imately 10 inches long, between the thrust side of the piston and the cylinder wall. Correct fit of the piston will require six to eight pounds pull to remove the feeler. Fit the pistons at normal room temperature (70°F). Pistons are available in standard size and oversizes of 0.003, 0.010, 0.020, 0.030 and 0.040 inch Figure 42—Fitting Pision in Cylinder Bore e. Fit Piston Pin (fig. 43). Fit the piston pin in the piston bosses with a medium thumb press fit with the piston and pin at room temperature. Fit the piston pin in the connecting rod bushing so that it will just hold its own weight with the pin and bushing clean and dry. f. Fit Piston Rings (fig. 44). Piston rings are available in standard size and oversizes of 0.003, 0.010, 0.020, 0.030 and 0.040 inch. Install stand¬ ard size rings if cylinder bore wear does not ex¬ ceed 0.002 inch out-of-round, or .0025 inch taper. If the cylinders are rebored, install the correct oversize rings. Measure the cylinder bore with an inside micrometer near the bottom of the pis¬ ton travel and select the correct size rings for 35x61 Figure 43—Fitting Piston Pin that size bore. Place the rings squarely in the bore, about two inches from the bottom, and measure the end gap. File the ends of the rings if necessary to obtain a gap of 0.007 inch to 0.015 inch. g. Assemble Pistons and Connecting Rods (fig. 40). Install the piston on the connecting rod, insert the piston pin through the piston and rod and install the lock rings. Recheck connect¬ ing rod alinement (subpar. c above). Install the rings on the piston as shown in figure 44 with a piston ring installing tool. 37. INTAKE AND EXHAUST MANIFOLD a. Disassemble and Inspect Manifolds. Re¬ move the side plates from the exhaust manifold and clean out the water jacket. Remove and 50 INSPECTION AND REPAIR OF ENGINE PARTS TM55-1146 37-38 PISTON RING-INTERMEDIATE (COMPRESSION RING) PISTON RING-UPPER (COMPRESSION RING) / PISTON RINGS-LOWER (OIL CONTROL RINGS) 3543 Figure 44—Piston Ring Set clean the small manifold ventilator tube con¬ nection. Remove the stud nuts which hold the intake and exhaust manifolds together and sep¬ arate the manifold. Clean accumulated carbon from the intake manifold heat chambers. In¬ spect the castings for cracks. Examine the gas¬ ket and replace if damaged. b. Assemble Manifolds and Measure Flange Height. Assemble the manifolds and check the flanges for being, parallel and flush. Lay a straightedge across the flanges and check for uniform height of the flanges. If a 0.010-inch feeler gage will pass between the straightedge and any of the flanges, shift the manifolds in re¬ lation to one another to overcome the uneven condition. If necessary, reface the flanges to make them even. 38. OIL PAN, STRAINER, FILTERS AND COOLER a. Inspect Oil Pan. Inspect the oil pan for cracks. Inspect the gasket surfaces and if found to be uneven, repair or replace the pan. b. Clean and Inspect Oil Strainer. Remove the strainer plate and screen and clean thorough¬ ly. Be sure that the strainer tube is open and clean. To assemble, shape the screen so that the relief hole in the center of the screen fully con¬ tacts plate. Install the strainer plate. c. Clean Oil Filters. (1) By-pass Absorption Type. Remove the cover and lift out the cartridge. Wash the filter and cover thoroughly in dry-cleaning solvent. Insert a new element in body, use a new cover gasket and install the cover. (2) Full-flow Strainer Type. Remove the filter head retaining ring and the oil filter case. Remove the large hex nut near center of the filter head and lift out the by-pass spring and ball. Re¬ move the drain plug from filter case. Wash all parts thoroughly in dry-cleaning solvent. Assem¬ ble the by-pass valve spring and ball in filter head. Use a new gasket and install hex nut. Place a new gasket between the oil filter case and head and secure with the filter head retaining ring. Use a new gasket and install the drain plug. (3) Full-flow Absorption Type. Remove the large acorn retaining nut and lift off the fil¬ ter cover. Remove filter elements from the filter body. Remove the hexagon plug opposite the pump to filter pipe connection and remove the relief valve, spring and plunger. Clean the inte¬ rior of the filter body and oil passages thorough¬ ly. Clean and install the relief valve plunger, spring and plug. Using new gaskets, place the body cylinder in place on the lower gasket and install the filter elements over the outlet sleeves at the bottom of the filter. Install the cover with the depressions in the cover over the upper ends of the filter elements. Install metal gasket and the cover retaining nut and tighten the nut to a tension of 50 foot pounds. d. Clean Oil Cooler. See paragraph 10 e. 51 TM55-1146 39 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section X ASSEMBLY OF ENGINE Assembly of engine. Tests after assembly. 39. ASSEMBLY OF ENGINE a. Install Camshaft Bearings. (1) General. Mount the cylinder block in an engine stand and turn the block bottom side up. Clean the camshaft bearing bores thorough¬ ly. The front ends of the camshaft bearings are chamfered to facilitate installation. An oil hole is machined in each bearing which must line up with an oil hole in the block. The rear bearing has a second oil hole which must line up with the hole which supplies oil to the timing gears. (2) Install Bearings. Install one bearing at a time, exercising care not to mar the inner or outer surface of the bearings. If the bearings are distorted or damaged in any way during the installation, the camshaft cannot be properly installed. The bearings are machined to size and require no reaming or burnishing after installa¬ tion. b. Install Tappets and Camshaft. Place the tappets in the guides out of which they originally came or to which they have been fitted. Coat the camshaft journals with oil, insert the shaft through the rear bearing and move it back into position. Do not burr or scratch the bearing with the edge of a cam or bearing journal. Install the cap screws which hold the thrust plate in place. c. Install Valves and Springs. Turn the block so that the cylinder head surface is up. Place the valve springs in position with the closely coiled end of the spring up and the spring re¬ tainers in the lower end of the spring. Lubricate the valve stems and install each valve in its proper guide. Use a valve spring compressing tool and compress the valve spring, then install the valve locks. Adjust the intake valve tappet clearance to 0.010 inch and the exhaust valve tappet clearance to 0.014 inch. d. Install Crankshaft and Bearings. (1) Assemble Gears to Crankshaft. In¬ stall keys in the end of the crankshaft and press the gear on the shaft. Paragraph . 39 . 40 (2) Install Crankshaft and Bearings. Turn the cylinder block bottom side up. Clean the crankshaft bearing bore and the upper half of the bearing inserts and install the inserts In the bore. Make sure that the oil hole in the bear¬ ing insert lines up with the oil hole in the bear¬ ing bore. Coat the bearings with oil and place the crankshaft in position. Clean the bearing caps and inserts and install the inserts in the caps. Make sure the tongue in the bearing insert fits in the groove in the bearing cap. Select the caps according to the punch marks and install all but one cap. (3) Measure Clearance and Install Caps AND Seals. To insure the proper fit of the bear¬ ings, place a one-inch strip of 0.002-inch brass shim stock inch wide between the remaining bearing cap and journal and install the screws (fig. 45). Tighten the screws to 75 to 80 foot pounds with a torque wrench, A drag will be felt when turning the shaft by hand if the clearance is correct. If no drag is felt, try the next under¬ size bearing (par, 34 d). Remove bearing cap and feeler stock and follow the same procedure to fit the rest of the bearings. Before finally install¬ ing the front bearing cap, install the L-shaped rubber gaskets on the top surface of the cap. 1/4-IN. WIDE AND l-IN. LONG 35x9 Figure 45—Measuring Crankshaft Bearing Clearance 52 ASSEMBLY OF ENGINE TM55-1146 39 When installing the cap see that the rubber gas¬ kets remain in position. After each bearing has been fitted individually, tighten all cap screws to 75 to 80 foot pounds with a torque wrench. e. Install Flywheel and Housing. Place the flywheel over the ends of the attaching bolts. Place the housing over the flywheel and dowel pins and install the attaching cap screws. Tap the flywheel against the crankshaft flange. Place the starting jaw flange over the flywheel bolts and install the lock washers and nuts. f. Install Piston and Connecting Rod Assem¬ blies (fig. 46). The connecting rods are numbered to correspond with the cylinder numbering; therefore, they must be installed in the proper cylinder bore. Clean the assemblies thoroughly and coat the pistons with oil. Compress the rings and insert the assemblies from the top of the bore with the oil hole in the bearing toward the valve side of the engine if engine runs clockwise (standard rotation) when viewed from the rear (reverse gear) end. Install the assemblies with the oil hole away from the valves if the engine runs in the opposite rotation. PISTON RING COMPRESSOR OIL HOLE Figure 46—Installing Piston and Connecting Rod Assembly in Standard Rotation Engine g. Install Connecting Rod Bearings (fig. 47). Install the upper insert and pull the connecting rod onto the crankshaft journal. Make sure the tongue in the insert fits in the groove in the rod. Place a one-inch strip of 0.002-inch brass shim stock inch wide lengthwise between the bear¬ ing insert cap and the journal, and install the cap. Tighten the nuts with a torque wrench to 45 to 50 foot pounds. A drag will be felt when rotating the crankshaft if the clearance is correct. Re¬ move bearing cap and shim stock and check the clearance on each connecting rod bearing indi¬ vidually. If no drag is felt, try the next under¬ size bearing (par. 34 d). When all connecting rod bearings have the desired clearance, install the bearing caps and tighten the bolt nuts to 45 to 50 foot pounds. 0.002-INCH SHIM 32X98 Figure 47—Measuring Connecting Rod Bearing Clearance h. Install Timing Gear Case. Install a new gasket on the timing case and place the case over the dowel pins in the cylinder block. Install the case attaching screws and tighten securely. i. Install Camshaft Gear and Tachometer Drive Gears. Place the timing gear oil tube in po¬ sition, with the end inserted in the hole in the end of the cylinder block, adjacent to the cam¬ shaft bearing, and secure with the clip and cap screw. Slide the camshaft gear through the opening at the top of the gear case. Turn the camshaft so that the gear can be installed over the end of hub key and with the timing mark registering with the marked tooth of the crank¬ shaft gear. Place the tachometer drive gear in place and install the cap screws which hold the gears to the hub. Make sure the timing gear oil tube is located so as to direct the oil on the cam¬ shaft gear. Install the tachometer drive pinion assembly to the gear case. j. Install Oil Pan (fig. 48). Remove the en¬ gine from stand. Coat the gasket recess in the front end of the oil pan and the flange with seal- 53 TM55-1146 39 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 direction. Insert the pump straight into position, being careful to keep the mounting holes in line with the holes in the block and not to disturb the shaft position before the pump gear meshes with the drive gear on the camshaft. Install the attaching screws and washers. 1. Install Distributor (fig. 50). Turn the ro¬ tor on the distributor to the “eight o’clock” posi¬ tion and insert the shaft into the cylinder block. Rotate the shaft slightly to the right or left until the tongue on the end of the distributor shaft meshes with the slot in the oil pump shaft. In¬ stall the cap screw in the advance control arm. GASKET-LEFT Do not cut off gasket ends, they will compress when oil pan screws are tightened GASKET-RIGHT GASKET-END 36x63 Figure 48—Oil Pan Gaskets ing compound and install a new end gasket, so that the ends stick up an equal distance above the flange. Do not cut the ends off as they will compress when the pan is installed. Place new gaskets on the flange and over the ends of the end gasket. k. Install Oil Pump (fig. 49). Rotate the en¬ gine until No. 1 piston is on the firing stroke. (No. 1 piston up, with both valves fully closed.) Place the gasket in position on pump and hold the pump as shown in figure 49. Turn the shaft so that the slot in the end of the shaft is parallel with the mounting holes in the pump body. Then turn the gear clockwise one tooth, if the engine runs clockwise when viewed from the rear (re¬ verse gear) end. Turn the gear one tooth coun¬ terclockwise if the engine runs in the opposite CLOCKWISE ALINE SLOT WITH HOLES SLOT IN SHAFT COUNTERCLOCKWISE 36 x 28 Figure 49 —Oil Pump Shaft Alined KOTOR AT "EIGHT O'CLOCK POSITION" 36 x 29 Figure 50—Distributor Rotor Alined m. Install Cylinder Head and Gasket (fig. 51). Clean all surfaces of the cylinder block and head thoroughly. Place the gasket and head in position and install the cylinder head stud nuts loosely; then, starting with the center nut, tight¬ en them with a torque wrench to 55 to 60 foot pounds in sequence shown in figure 51. n. Install Valve Spring Covers. Place the valve spring cover gaskets and covers in place and install the attaching nuts. o. Install Generator. (1) Six Volt. Place a new gasket over the generator mounting studs. Install the generator over the studs with the drive gear in mesh with the camshaft gear. Install the attaching stud nuts with plain washers and lock washers on two studs and spring clip and lock washers on the upper inner stud. MOUNi’NG HOLES 54 TM55-1146 39-40 ASSEMBLY OF ENGINE 36x59 Figure 51—Cylinder Head Tightening Sequence (2) Twelve Volt. Mount the generator in the bracket, install and adjust drive belt. p. Install Water Pump. Place a new gasket on the water pump mounting flange. Install the pump in the timing gear case with the drive gear in mesh with the generator drive gear. Install the attaching cap screws with lock washers. q. Install Starting Motor and Oil Pressure Relief Valve. Place the starting motor in position on the flywheel housing and install the mounting cap screws. Place the oil pressure relief valve, plunger, and spring into the cylinder block and install the hexagon plug with a good gasket. r. Install Spark Plugs, Cables, Coil and Dis¬ tributor Cap. Install the spark plugs and tighten to 26 to 32 foot pounds. Place the cable assembly over the mounting studs and install lock wash¬ ers and nuts. Position the distributor cap on the distributor and engage the two cap spring clips. Attach the ignition coil to the cylinder head and connect the wires. s. Install Fuel Pump and Crankcase Ventila¬ tor. Place a new gasket on the fuel pump mount¬ ing flange and install the pump on the cylinder block. Place the open end of the air silencer sup¬ port arm in the cylinder block and install the at¬ taching screw. t. Install Manifold Assembly. Install new manifold gaskets over the studs. Slide the mani¬ fold assembly into place and install the attaching washers and nuts. Connect the small manifold ventilator tube between the manifold and the cylinder head. u. Install Oil Cooler and Filters. Place the oil cooler and Alters in their respective positions and install the attaching cap screws. V. Install External Oil and Water Pipes. In¬ stall all external oil and water pipes, using new gaskets in the water pipe connections. w. Install Carburetor. Place a gasket and the carburetor over the studs and install the at¬ taching nuts. Install the fuel tube between the fuel pump and carburetor. X. Install Air Silencer and Flame Arrester Assembly. Slide the assembly over the carbure¬ tor air horn and install cap screw through the crankcase ventilator. Tighten the clamp screw at the carburetor air horn. y. Install Reverse and Reduction Gear As¬ sembly. Suspend the reverse and reduction gear assembly on a hoist so that it can be rocked slightly to engage the pinion gears with the crankshaft gear. Hold the mounting flange paral¬ lel and centered with the flange of the timing gear case and move the assembly into place over the bearings. Install the mounting cap screws. Strike the starting jaw on the front of the crank¬ shaft with a soft hammer to relieve any end thrust that may have been imposed on the shaft by the installation of the reduction gear assem¬ bly. 40. TESTS AFTER ASSEMBLY a. General. When a new or rebuilt engine is put in service, make the tests and adjustments listed below to assure satisfactory performance. (1) Adjust Carburetor. See paragraph 22 a. (2) Check Choke Adjustment. See para¬ graph 22 b. (3) Test Fuel Pump. See paragraph 22 c. (4) Tighten Cylinder Head. Tighten stud nuts to 55 to 60 foot pounds with engine at nor¬ mal operating temperature. 55 TM55-1146 41-42 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section XI CARBURETOR Paragraph Description. 41 Disassembly and inspection. 42 Assembly. 43 41. DESCRIPTION a. Description. The Zenith carburetor (model 556-M3) is of the updraft type. Different functional systems are built into the carburetor to provide maximum efficiency under varied operating conditions. ( 1 ) Float System. A metal float actuates a needle valve maintaining the correct fuel level with relation to the fuel metering systems. (2) Idling System. The idling system sup¬ plies the fuel mixture during the idle range. An adjustable screw controls the idling mixture ratio. (3) Accelerating System. An accelerat¬ ing pump actuated by manifold vacuum momen¬ tarily delivers additional fuel while accelerating. (4) Main Metering System. The main metering system meters the fuel that is used in the normal operating range. The fuel mixture ratio is controlled by an adjustment needle screw. (5) Power System. The vacuum operated piston automatically operates a power valve which meters fuel for full load operation in addi¬ tion to the fuel supplied by the main metering system. (6) Choke System. The choke system pro¬ vides means of restricting the air supply to en¬ rich the mixture for starting and warming up. 42. DISASSEMBLY AND INSPECTION a. General. Wash the exterior of the carbu¬ retor assembly in dry-cleaning solvent and dry with compressed air. b. Remove Union Body and Filter Screen. Remove the filter plug, screen and union body. Slide the screen off the filter plug. Wash the screen in dry-cleaning solvent and blow clear with compressed air. Replace the screen and fiber washers if damaged. c. Remove Upper Body Assembly (fig. 52). Remove the two attaching screws and lift the upper body assembly off the fuel bowl assembly. UPPER BODY ASSEMBLY BODY GASKET FUEL BOWL ASSEMBLY 36x30 Figure 52—Removing Upper Body Assembly d. Remove Body Gasket and Idling Jet (fig. 53). Lift off the body gasket and screw out the idling jet. Inspect the idling jet and replace it if damaged or if other than a No. 11 jet. e. Remove Vacuum Pump Assembly (fig. 54). Push the pump piston down against the spring tension, then pull up sharply to pull the pump Figure 53—Removing Idling Jet 56 TM55-1146 42 CARBURETOR Figure 54—Removing Vacuum Pump Assembly assembly out of the upper body casting. Inspect the pump assembly and if damaged or if the pis¬ ton is worn, replace the assembly. f. Remove Float and Float Valve and Seat Assembly (figs. 54 and 55). Push the float axle pin out from the slotted side of the hinge bracket (fig. 54). Shake the float and if there is gasoline inside the float, indicating a leak, replace the float. Screw out the float valve and seat assem¬ bly (fig. 55). Examine the valve and seat and if either is scored or damaged, replace the valve and seat assembly. g. Remove Venturi (fig. 56). Remove ven¬ turi retainer screw and pull out the venturi. Figure 56—Removing Venturi I h. Remove Throttle Plate and Shaft. Remove the screws which hold the throttle plate in the shaft and lift out the plate. Drift the taper pin from the throttle lever bushing. Drift the shaft through the bushing and remove from the body assembly. Inspect the throttle plate, shaft and bushing and replace worn or damaged parts. If bushings are to be replaced, screw a tap into bushing and drift against end of tap to remove the bushing. Press new bushings into place and line ream the bushings with special Zenith reamer, C161-71-3. i. Remove Idling Needle Valve (fig. 53). Re¬ move the adjustable idling needle valve and spring. Inspect the seating surface of the needle and if scored or damaged, replace the needle valve. ADJUSTING NEEDLE MAIN JET ADJUSTMENT ASSEMBLY 36x34 FLOAT HINGE BRACKET 32X4 FLOAT VALVE AND SEAT ASSEMBLY Figure 55—Removing Float Valve and Seat Assembly Figure 57—Main Jet Adjustment Assembly Removed 57 TM55-1146 42 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 36x35 Figure 58—Removing Main Jet j. Remove Main Jet Adjustment Assembly (fig. 57). Screw the adjustment assembly from the float bowl assembly. Inspect the needle and if the seating surface is scored or damaged or if the needle is bent, replace the assembly. Exam¬ ine the fiber washer and needle packing and re¬ place if damaged. k. Remove Main Jet (fig. 58). Screw out the main jet. Replace the jet if the orifice is ques¬ tionable or if not a No. 29 jet. l. Remove Accelerating Pump Check Valve (fig. 59). Screw out the check valve. Clean and examine the valve and replace if questionable. m. Remove Power Jet Valve Assembly (fig. 60). Use special Zenith wrench, No. 161-81, and screw out the power jet. Examine the valve Figure 59—Removing Accelerating Pump Check Valve Figure 60—Removing Power Jet Valve Assembly and spring and if questionable, replace the as¬ sembly. n. Remove Progressive Well (fig. 61). Screw out the progressive well. Clean thoroughly and inspect. If the orifices show signs of having been altered or damaged, replace the part. o. Remove Discharge Tube Assembly (fig. 62). Use special Zenith wrench. No. 161-25, and screw out the discharge tube, being careful not to damage the tip of the cap jet. Screw the power and accelerating jet from the end of the dis¬ charge tube. Clean and inspect the parts. Re¬ place the jet if the size of the orifice is question¬ able or if other than a No. 17 jet. Figure 61—Removing Progressive Well 58 CARBURETOR TM55-1146 42-43 36x39 DISCHARGE TUBE p. Remove Cap Jet (fig. 63). With special Zenith wrench, No. 161-25, screw out the cap jet. Inspect the jet and if damaged or if other than a No. 32 jet, replace the jet. q. Remove Suction Jet (fig. 64). Screw out the suction jet. Make sure the jet orifice and tube are clean. If the jet is damaged or is other than a No. 15 jet, replace the part. r. Remove Compensating Jet (fig. 65). Re¬ move the compensating jet from the inside of the float bowl. Replace the jet if damaged or other than a No. 32 jet. s. Remove Air Shutter Plate and Shaft (fig. 65). Remove the screws which hold the plate to the shaft. Remove the lever from the shaft and Figure 62—Removing Discharge Tube slide the shaft out of the body. Inspect the plate and poppet valve assembly and replace if dam¬ aged in any way. Figure 65—Removing Compensating Jet t. Clean and Inspect Fuel Bowl and Upper Body Castings. Remove threaded passage plugs. Clean all passages with cleaning solution and blow out with compressed air. Install the pas¬ sage plugs. Clean all traces of carbon from the throat of the upper body casting. Inspect the vacuum cylinder and if scored or damaged, re¬ place the fuel bowl. a. General. Be sure all parts are clean, par¬ ticularly the passages and jet orifices. Install new gaskets and fiber washers whenever the , original one is questionable. 36x41 Figure 64—Removing Suction Jet CAP JET 36x40 Figure 63—Removing Cap Jet SUCTION JET AIR SHUHER PLATE COMPENSATING JET SHAFT AND LEVER 36x42 43. ASSEMBLY . / 59 TM55-1146 43 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 b. Install Air Shutter Shaft and Plate. Place the fuel bowl on the bench with the float chamber to the right. Slide the air shutter shaft through the body and into position with the flat side up. Install the lever on the end of the shaft and con¬ nect the lever spring. Install the air shutter plate with the poppet valve up and the spring out. Make sure the shutter plate is centered and does not bind and that the lever spring opens the shutter. c. Install Compensating Jet. Place a fiber washer on a No. 32 compensating jet and screw the jet into position in the float chamber (fig. 65). d. Install Suction Jet. Place a fiber washer # over a No. 15 suction jet and screw the jet into place at the edge of the carburetor throat (fig. 64). e. Install Cap Jet. Place a fiber washer over the threaded end of a No. 32 cap jet and screw the jet into the carburetor throat (fig. 63). f. Install Power and Accelerating Jet and Discharge Tube. Install a fiber washer over a No. 17 power and accelerating jet and screw the jet into the discharge tube. Place another fiber washer against the shoulder of the discharge tube and screw the tube into the center of the carburetor throat being careful not to damage the tip of the cap jet (fig. 63). Figure 66—Installing Throttle Plate left. Slide the shaft through the body from the left, with the countersunk holes forward. Install the throttle lever bushing and the taper pin. In¬ sert the throttle plate through the shaft with the cutout down and forward. Hold the throttle plate closed and install the attaching screws. 1. Install Venturi (fig. 67). Stand the upper body casting on the manifold flange and slide the venturi into the throat with the^ larger opening first. Install the lock screw with a lock washer. g. Install Power Jet Valve Assembly. Install the power jet valve in the bottom of the vacuum cylinder (fig. 60). Use special Zenith wrench No. 161-81. h. Install Accelerating Pump Check Valve. Install the check valve in the bottom of the offset in the fuel chamber (fig. 59). i. Install Progressive Well. Screw the pro¬ gressive well into the face of the fuel bowl adja¬ cent to the vacuum cylinder (fig. 61). j. Install Main Jet and Main Jet Adjustment. Place a fiber washer over a No. 29 main jet and screw the jet into place from the outside of the fuel bowl (fig. 58). Place a fiber washer over the main adjustment fitting and install the fitting over the main jet. Screw the main adjustment needle assembly (fig. 57) through the fitting until the needle just contacts the seat, then back it out two turns and tighten the packing nut. k. Install Throttle Shaft and Plate (fig. 66). Place the upper body casting on a bench with the manifold flange up and the number disk to the m. Install Float Seat and Valve and Float. Place a fiber washer over the threaded end of the float valve seat and screw the seat into the upper body. Place the float valve in the seat. Hold the float in position and push the float axle, cham- VENTURI RETAINER SCREW AND LOCKWASHER VENTURI 36x44 Figure 67—Venturi Installed 60 CARBURETOR TM55-1146 43 fered end first, through the solid side of the bracket and through the float hinge (fig. 55), n. Check Float Level (fig. 68).. Stand the body on the manifold flange and measure the dis¬ tance from the gasket surface of the body to the top edge of the float. If the distance is not 2% inches (plus or minus inch) use long nose pliers and bend the float lever close to the float to obtain the correct measurement. Do not apply pressure to the float when setting the float level. Be sure the float is in line with the float cham¬ ber after adjustments are made. o. Install Vacuum Pump and Body Gasket. Insert the beveled end of the pump assembly and the spring retainer into the opening in the upper body (fig. 54). Install a new body gasket against the body flange. p. Install Idling Jet and Idling Needle Valve. Screw a No. 11 idling jet into the opening adja¬ cent to the vacuum pump (fig. 53). Place the coiled spring over the idling needle valve and screw the needle into the body until it just con¬ tacts its seat, then back the needle out IV 2 turns. Do not use a screw driver or pliers and force the needle on its seat as such a procedure would ruin the needle or seat. q. Install Upper Body Assembly. Assemble the upper body to the fuel bowl, being careful not to damage the idling jet or the vacuum piston, and install the attaching screws (fig. 52). To make certain that the float is free to function, turn the carburetor upside down quickly and listen for movement of the float. If no movement is evident, remove the upper body and aline the float. r. Install Union Body and Filter Screen. Place a fiber washer over the filter plug and slide the filter screen on the plug. Place the union body and another fiber washer over the filter screen and screw the assembly into place. 61 TM55-1146 44-46 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section XII FUEL PUMP Paragraph Description. 44 Disassembly and inspection. 45 Assembly. 46 44. DESCRIPTION a. Description. The fuel pump consists main¬ ly of a diaphragm and inlet and outlet valves. It is operated by an eccentric on the engine cam¬ shaft through a rocker arm which actuates the diaphragm. d. Remove Diaphragm and Rocker Arm. Un¬ hook the diaphragm from the diaphragm link (fig. 69). Drift the rocker arm pin out of the pump body and remove the rocker arm and dia¬ phragm link. Inspect the pump body oil seal .and replace if worn or damaged. I 45. DISASSEMBLY AND INSPECTION a. Remove, Clean and Inspect Filter Body. Remove the filter bowl from the pump. Wash the filter bowl and filter in clean gasoline. Inspect parts and replace filter or gasket if damaged. b. Remove Cover and Valves (fig. 72). Re¬ move the screws which hold the cover and dia¬ phragm to the pump body. Remove the valve re¬ tainer plate and the valves. Wash the valves in a suitable solvent and inspect the valves and-gas- kets. If the pump is inoperative and the dia¬ phragm and actuating mechanism are in good condition, replace the valve assemblies. c. Inspect Diaphragm and Rocker Arm. If diaphragm is broken or damaged or if rocker arm parts are worn, replace the necessary parts. AND SHAFT 36x46 46. ASSEMBLY a. Install Rocker Arm. Insert the diaphragm link and the rocker arm into the pump body with the hook on the link away from the diaphragm and the spring lug on the rocker arm toward the diaphragm. Aline the piij holes and carefully drift the diaphragm pin into place. Place washer over the pin and rivet the end of the pin slightly. b. Install Diaphragm (fig. 70). Place the spring seat and spring over the diaphragm shaft. Hold the diaphragm link against the body oil seal by pressing on the outer end of the link with thumb and hook the diaphragm to the link. c. Install Valves. Place a paper gasket in each valve port. Install the valves as shown in figure 71. Figure 69—Unhooking Diaphragm from Link Figure 70—Hooking Diaphragm to Link 62 TM55-1146 46 FUEL PUMP ATTACHING SCREW VALVE RETAINER PLATE 36x48 VALVE WITH SPRING UP VALVE WITH SPRING DOWN Figure 71—Valves Installed d. Install Pump Cover (fig. 72). Insert the cover attaching screw through the cover and diaphragm and start the screws into the pump body. Hold the rocker arm to the end of its stroke against the spring tension, while tightening the cover to body screws. Install rocker arm spring. PUMP COVER 36x49 ROCKER ARM COVER AHACHING SCREW Figure 72—Tightening Cover to Body Screws e. Install Filter. Place the filter, gasket and ' filter bowl in position and tighten the bail nut. 63 TM5S-1146 47-48 ENGINE, GASOUNE, MARINE, CHRYSLER CROWN, MODEL M7 Section Xm WATER PUMP Paragraph Description. ^ Disassembly and inspection. 48 Assembly. 49 47. DESCRIPTION a. Description. The dual drive water pump is mounted on the timing gear case. Both shafts are driven from the camshaft gear through steel drive gears which are lubricated by engine oil. The pump driven gears are moulded rubber gears with brass hubs. The pump requires no lubrica¬ tion other than that supplied by the engine oiling system. DRIVE GEAR—UPPER PACKING NUT shaft-UPPER SHAFT OIL SEAL MOUNTING SCREW AND LOCK WASHER PIN '' ,KEY \ MOUNTING GASKET BODY ASSEMBLY COVER STUD SHAFT BUSHINGS—FRONT shaft—LOWER SHAFT OIL SEAL DRIVE GEAR—LOWER COVER STUD NUT AND LOCK WASHER DRIVEN GEAR HOUSING AND COVER AND GASKET GASKET SHAFT BUSHINGS- REAR KEYS DRIVEN GEARS PACKING NUT- PACKING DRAIN COCK 32X122 Figure 73—Water Pump Disassembled Figure 74—Pump Gears Marked Before Removal 48. DISASSEMBLY AND INSPECTION a. Remove Rubber Driven Gears and Shafts. Remove the stud nuts and the pump cover. Mark the rubber driven gears so that they can be in¬ stalled on the shaft from which they are removed and in the original mesh with each other (fig. 74). Press the pump shafts out of the driven gears and pull the shafts and drive gears from the pump body. Tap the housing and driven gears off the mounting studs and remove thss. gears from the housing (fig. 75). b. Remove Packing Nuts and Packing (fig. 73). On standard rotation engines, turn the low¬ er packing nut counterclockwise and the upper packing nut clockwise to remove. If the engine runs in the opposite rotation, turn the lower packing nut clockwise and the upper nut coun¬ terclockwise to remove. Remove the packing from the bushing retainers. 64 TM55-1146 48-49 WATER PUMP 32X103 BODY DRIVE GEAR AND SHAFT—LOWER DRIVE GEAR AND SHAFT-UPPER DRIVEN GEAR DRIVEN GEAR HOUSING DRIVEN GEAR Figure 75—Pump Gears and Shafts Removed c. Remove Pump Shaft Bushings and Oil Seals (fig. 73). Press the front bushings and shaft oil seals out of the pump body from the out¬ side. Drift the rear bushings out of the packing glands from the inside. d. Inspection. Thoroughly clean and inspect all parts and replace parts that are worn or dam¬ aged. Remove pins and press drive gears off the shafts if gears or shafts are to be replaced. Re¬ place the shaft oil seals if at all questionable. 49. ASSEMBLY a. Install Front and Rear Bushings (fig. 76). Press the front bushings into the pump body from the outside until the outer end of the bush¬ ings are flush with the pump body. Press the rear bushings into the bushing retainer until the outer end of the bushings protrude %2 inch above the retainer. If new bushings are installed, line ream the bushings if necessary to provide a free running fit of the shaft. b. Install Oil Seals and Packing. Place the shaft oil seals in the pump body with the crimped side first so that the free edge of the seal leather will be toward the bushing. Press the seals flush with the body casting. Place two new pieces of packing, with the flat surfaces together, into each bushing retainer and just start the packing nuts. c. Install Pump Shafts and Gears. (1) New Shafts or Drive Gears. When installing new shafts or drive gears, place a woodruff key in the upper shaft (the shaft with key way on each end) and place the wider of the two drive gears over the key with the extended end of the hub first. Press the gear onto the shaft until only 5‘^%2 inches of the shaft is ex¬ posed, then drill the shaft and install the pin. Slide the upper shaft into the pump body. Place a new gasket over the gear housing studs and in¬ stall the housing with the drain cock down. In¬ stall key and pump driven gear on the upper shaft and press the gear down until the brass hub is flush with the end of the shaft. Slide the lower shaft into place and install the key and driven gear flush with the end of the shaft. Install the drive gear over the drive end of the shaft and in mesh with drive gear on the upper shaft. Press the gear flush with the end of the shaft and drill and install pin. Figure 76—Water Pump Bushings Installed 65 TM55-1146 49 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 (2) Original Shafts AND Drive Gears. In¬ sert the upper shaft through the pump body. Place a new gasket over the gear housing studs and install the housing with the drain cock down. Install key in shaft and press the driven gear on the shaft until the brass hub of the gear is flush with the end of the shaft. If the driven gears were marked before being removed, install the lower gear in the housing in its origi¬ nal relation with the upper gear (flg. 74). Install the lower shaft so that the keyways in the shaft and gear are in perfect alinement when the drive gears are in mesh. If the driven gears were not marked before being removed or if new driven gears are being installed with the original shafts and drive gears, it may be necessary to shift the mesh of both the driven gears and the drive gears several times to get proper alinement of the keyways and avoid distortion of the driven gear teeth. When proper alinement has been es¬ tablished, install the key and press the lower gear on the shaft until the brass hub is flush with the end of the shaft. d. Install Pump Cover and Tighten Packing Nuts. Place a new gasket over the housing studs and install the cover. Tighten the packing nuts by turning them in the reverse direction from that given in paragraph 48 b for removal. 1 66 OIL PUMP TM55-1146 50-51 Section XIV OIL PUMP Description. Disassembly and inspection Assembly. Paragraph . 50 . 51 . 52 50. DESCRIPTION a. Description. The gerotor type oil pump is mounted on tho side of the engine and is driven by a spiral gear on the camshaft. The pump as¬ sembly consists of a drive shaft and an inner and outer rotor, closely fitted in the oil pump body. outer rotor is less than 0.747 inch or the diameter is less than 2.244 inches, replace the rotor. If the length of the inner rotor is less than 0.747 inch, drift out the pin, press the shaft from the rotor and install a new rotor. d. Inspect Pump Body. Make certain the DRIVE GEAR PIN OIL PUMP ROTOR—INNER OIL PUMP ROTOR—OUTER OIL PUMP AND DISTRIBUTOR DRIVE GEAR OIL PUMP BODY OIL PUMP DRIVE SHAFT OIL PUMP ROTOR PIN OIL COVER OIL PUMP COVER SCREV/-^"^ AND LOCK V/ASHER 32x41 LENGTH INNER ROTOR OUTER ROTOR-1 DIAMETER 32x42 LENGTH Figure 77—Oil Pump Disassembled Figure 78—Measurements of Pump Rotors 51. DISASSEMBLY AND INSPECTION a. Remove Cover and Outer Rotor (fig. 77). Remove the cover and cover gasket. Hold hand over the cover opening and with the pump upside down turn the drive shaft until the rotor slips out. b. Remove Inner Rotor and Drive Shaft (fig. 77). Drift out the straight pin which holds the pump drive gear to the end of the drive shaft. Press the shaft out of the gear, then slide the shaft and rotor out of the pump body. c. Inspect Pump Rotors (fig. 78). Wash all parts of the pump in dry-cleaning solvent and dry with compressed air. Measure the diameter and length of the outer rotor and the length of the inner rotor with micrometer. If the length of the body and rotors are perfectly clean, then place the rotors in the pump body. Place a straight¬ edge across the pump body between the screw holes and measure the clearance between the top of the rotors and the straightedge (fig. 79). Sub¬ tract from this measurement any rotor wear (subpar. c above) and if the remainder of the measurement exceeds 0.004 inch, replace the pump body. Measure the clearance between the diameter of the outer rotor and the pump body with a feeler gage (fig. 80). Subtract from this measurement any wear on the diameter of the rotor (subpar. c above) and if the remainder of the measurement exceeds 0.004 inch, replace the pump body. e. Inspect the Pump Body Cover (fig. 81). Lay a straightedge across the inner surface of 67 TM55-1146 51-52 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Figure 79—Measuring Depth of Pump Body Figure 81—Inspecting Pump Body Cover 32x43 STRAIGHT EDGE FEELER GAGE PUMP COVER 32x4S STRAIGHT EDGE FEELER GAGE PUMP BODY OUTER ROTOR 32x44 DRIVE GEAR FEELER GAGE 32x46 PUMP BODY Figure 80—Measuring Clearance Between Body and Rotor • the pump cover and check the surface with a feeler gage. If the surface is not flat, indicating wear, replace the cover. 52. ASSEMBLY a. Install Inner Rotor and Shaft (fig. 82). Press the inner rotor on the drive shaft until the end of the shaft is flush with face of the gear and install the pin.'Insert the shaft through the pump body and press the drive gear on the shaft until the end play in the shaft is 0.003 to 0.008 inch. Measure' the clearance between the end of the housing and the end of the gear with a feeler Figure 82—Measuring Pump Drive Shaft End Play gage. If the pin holes in the gear and shaft do not line up lengthwise of the shaft when the proper end play is established, drill a new pin hole through the gear and the shaft at the opposite angle and between the old hole and the gear teeth. Install the pin and rivet the ends to hold it in place. b. Install Outer Rotor and Cover. Slide the outer rotor into place. Place a new cover gasket in the gasket recess in the pump body and install the cover. Draw the cover attaching cap screws down evenly to get uniform contact with the gasket and avoid distortion of the cover. 68 TM55-1146 53-54 GENERATOR Section XV GENERATOR Paragraph Description. 53 Disassembly and inspection ( 6 -volt generator). 54 Assembly ( 6 -volt generator). 55 Disassembly and inspection ( 12 -volt generator). 56 Assembly ( 12 -volt generator). 57 Bench tests. 58 53. DESCRIPTION a. Description. The generator is of the shunt type. The output of the generator is controlled by a three-unit regulator assembly consisting of a circuit breaker, current control unit and a voltage regulator. 54. DISASSEMBLY AND INSPECTION (6-VOLT GENERATOR) a. Test Brush Spring Tension and Inspect Brushes. Remove the head band clamp bolt and the band. Insert a piece of medium weight paper between one of the brushes and the commutator and attach a spring scale to the brush arm. Pull on the scale at right angles to the arm and note the scale reading at the instant the paper is free. If the reading is less than 45 ounces or more than 53 ounces, replace the brush spring. Test the ten¬ sion of the other spring in the same manner. Re¬ move the terminal screws which attach the brush pigtails to the brush holders. Pull the brush arms away from the brushes and pull out the brushes. Compare the brushes with a new brush. If they are worn to less than half their original length or are oil soaked, replace them. b. Remove and Disassemble Commutator End Plate. Remove the end cover and gasket. Remove the two long frame screws and remove the commutator end plate (fig. 83). Test the in¬ sulated brush holder for ground (fig. 84). Touch one lead from a test lamp to the insulated brush holder and the other lead from the lamp to the end plate. If test lamp lights, replace the end plate as the holder is grounded. Inspect armature shaft bushing and if worn or damaged, remove the oil wick, press the bushing out of the end plate, and install a new bushing and oil wick. Hold the loop of the springs out of the notch of the brush holder and slide the brush arms off the pins. c. Remove and Disassemble Drive End Plate (fig. 83). Separate the mounting adapter from the drive end head, if attached. Remove the drive gear nut and pull the gear off the armature shaft. Remove the gear drive key from the shaft and rDRIVE GEAR NUT AND LOCK WASHER GENERATOR FRAME FRAME SCREW COMMUTATOR END PLATE HEAD BAND OIL THROWER DRIVE GEAR REAR BEARING ARMATURE DRIVE GEAR KEY OIL SEAL RETAINER SCREWS \ FRAME SCREW BRUSHES 32x68 Figure 83—Generator Disassembled (6-Volt) 69 TM55-1146 54 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 GROWLER SWITCH-OFF INSULATED BRUSH HOLDER GENERATOR END PLATE TEST PRODS TOUCH ONE PROD TO INSULATED BRUSH HOLDER AND OTHER PROD JO END PLATE— IF TEST LAMP LIGHTS THE BRUSH HOLDER IS GROUNDED GROWLER TEST LAMP SWITCH-ON 32x69 STEEL STRIP ARMATURE SEGMENTS GROWLER GROWLER SWITCH-LOW HOLD STEEL STRIP PARALLEL WITH AND AGAINST ARMATURE SEGMENTS, ROTATE ARMATURE SLOWLY—IF STEEL STRIP VIBRATES ARMATURE IS SHORT CIRCUITED TEST LAMP SWITCH-OFF 32x71 Figure 84—Testing Insulated Brush Holder Figure 86—Testing Generator Armature for Short Circuit slide off the oil thrower and drive end plate. Re¬ move the oU seal retainer, the felt oil seal and bearing from the head. Inspect the bearing and if worn or rough, replace it. d. Inspect and Test Armature. (1) Inspect Commutator AND Shaft. In¬ spect the commutator and if worn or burned or eccentric more than 0.002 inch, turn down the segments and undercut the mica. Inspect the shaft for proper fit in the rear bushing. If the shaft is rough or worn, install a new bushing and armature. shaft and the other lead from the lamp to the commutator segments. If the test lamp lights, the armature is grounded. (3) Test Armature for Short Circuit (fig. 86). Place the armature in a growler and turn growler switch to the low position. Hold a steel strip parallel with and against the armature segments and rotate the armature slowly. If the steel strip vibrates, the armature is short cir¬ cuited. e. Test Field Coils. (2) Test Armature for Ground (fig. 85). Touch one lead from a test lamp to the armature GROWLER COMMUTATOR SEGMENTS TEST PROD TEST PROD TOUCH ONE PROD TO ARMATURE SHAFT AND OTHER PROD TO COMMUTATOR SEGMENTS— IF TEST LAMP LIGHTS, THE ARMATURE IS GROUNDED GROWLER SWITCH-OFF GENERATOR ARMATURE TEST LAMP SWITCH-ON 32x70 Figure 85—Testing Generator Armature for Ground (1) Test for Open Circuit (fig. 87). Con¬ nect one lead from a test lamp to the field termi¬ nal and the other lead from the lamp to the field GENERATOR FRAME AND FIELD COILS FIELD TERMINAL POST FIELD LEAD WIRE Figure 87—Testing Field Coils for Open Circuit 70 TM55-1146 54-55 GENERATOR 32x73 Figure 88—Testing Field Coils for Ground lead wire. If the lamp does not light, there is a break in the coil wiring. (2) Test for Ground (%. 88). Touch one lead from a test lamp to the generator frame and the other lead from the lamp to the field terminal post. If the lamp lights, the field coils are grounded. f. Remove Field Coils. Remove the nuts from the field and armature terminal posts and push the posts to the inside of the generator frame. Remove the large countersunk screws which hold the field poles to the generator frame and remove the field poles and coils. 55, ASSEMBLY (6-VOLT GENERATOR) a. Install Field Coils. Slide the field coils and field poles into the generator frame with the brush lead wire and terminal post adjacent to the armature terminal post hole. Install the insula¬ tion strip inside the generator frame and insert terminal posts through the insulating strip and frame. Install the insulating washers and binder nuts on the terminal posts and install the coun¬ tersunk screws which hold the field poles to the frame. Tighten the screws as tight as possible with a large screw driver and stake. b. Install Armature and Drive End Plate (fig. 83). Oil the ball bearing and place it in the plate. Install the felt oil seal against the bearing and assemble the oil seal retainer to the plate. Slide the plate and oil thrower on the armature shaft. Place the drive gear key in the shaft and install the drive gear lock washer and nut. Slide the armature into the generator frame. c. Install Commutator End Plate and Brushes (fig. 83). Place the brush arms and springs over the pins in the end plate. Install the end plate on the frame with the hole in the plate over the dowel pin in the frame and install the frame screws. Install the plate cover and gasket. Hold the brush arms out against the spring ten¬ sion and slide the brushes into the brush holders with the angle on the brushes conforming to the contour of the commutator. Connect the brush pigtails and the lead wire from the armature post to the brush holder. Be certain that the brush lead terminals do not contact the generator frame. Place the head band in position and install the clamp bolt. BEARING RETAINING SCREW AND WASHER rOIL GUARD (COMMUTATOR END PLATE FELT WASHER | lilfia /HEAD BAND FRAME BEARING BRUSHES END CAP COVER FRAME SCREWS BEARING RETAINER FELT WASHER RETAINER—INNER BEARING . FELT WASHER—OUTER PULLEY LOCK WASHER DRIVE END HEAD FELT WASHER RETAINER—OUTER FELT WASHER—INNER 32X131 Figure 89—Generator Disassembled (1'2-Volt) 71 TM55-1146 56-57 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 56. DISASSEMBLY AND INSPECTION , (12-VOLT GENERATOR) a. Test Brush Spring Tension and Inspect Brushes. Remove the head band clamp bolt and the band. Insert a piece of medium weight paper between one of the brushes and the commutator and attach a spring scale to the brush arm. Pull on the scale at right angles to the arm and note the scale reading at the instant the paper is free. If the reading is less than 64 ounces or more than 68 ounces, replace the brush spring. Test the tension of the other spring in the same man¬ ner. Remove the terminal screws which attach the brush pigtails to the brush holders. Pull the brush arms away from the brushes and pull out the brushes. Compare the brushes with a new brush. If they are worn to less than half their original length or are oil soaked, replace them. b. Remove and Disassemble Commutator End Plate (fig. 89). Remove the end cap cover and gasket and remove the bearing retaining screw and washer from the end of the armature shaft. Remove the two long frame screws and remove the end plate. Inspect the armature shaft bearing and if worn or damaged push the bear¬ ing out of the end plate and install a new bearing. Test the insulated brush holder for ground (fig. 86). Touch one lead from a test lamp to the in¬ sulated brush holder and the other lead from the lamp to the end plate. If the test lamp lights, re¬ place the end plate. Hold the loop of the springs out of the notch of the brush holders and slide the brush arms off the pins. c. Remove and Disassemble Drive End Head (fig. 89). Pull the drive end head and armature from the generator frame. Remove the armature shaft nut and the pulley. Remove the pulley drive key and the end head. Remove the bearing retainer, bearing and felt washers from the end head. Inspect the bearing and if worn or rough, replace the bearing. d. Inspect and Test Armature. (1) Inspect Commutator and Shaft. In¬ spect commutator and if worn or burned or ec¬ centric more than 0.002 inch, turn down seg¬ ments and undercut mica. (2) Test Armature for Ground. Touch one lead from a test lamp to the armature shaft and the other lead from the lamp to the commu¬ tator segments (fig. 85). If the test lamp lights, the armature is grounded. (3) Test Armature for Short Circuit. Place the armature in a growler and turn growler switch to low position. Hold a steel strip parallel with and against the segments and rotate the armature slowly (fig. 86). If the steel strip vi¬ brates, the armature is short circuited. e. Test Field Coils. (1) Test for Open Circuit. Touch one lead from a test lamp to the field terminal and the other lead from the lamp to the armature ter¬ minal post (fig. 87). If the lamp does not light, there is a break in the coil wiring. (2) Test FOR Ground. Touch one lead from a test lamp to the generator frame and the other lead from the lamp to either the field or armature terminal post (fig. 88). If the lamp lights, the field coils are grounded. f. Remove Field Coils. Remove the nuts from the field and armature terminal posts and push the posts to the inside of the generator frame. Remove the large countersunk screws which hold the field pieces to the generator frame and remove the field pieces and coils. 57. ASSEMBLY (12-VOLT GENERATOR) a. Install Field Coils. Slide the field coils and field pieces into the generator frame with the brush lead wire and terminal post adjacent to the armature terminal post hole. Install the insulation strip inside the generator frame and insert the terminal posts through the insulating strip and frame. Install the insulating washers and binding nuts on the terminal posts and in¬ stall the countersunk screws which hold the field pieces to the frame. Tighten the screws as tight as possible with a large screw driver and stake. b. Install Drive End Head and Armature (fig. 89). Install a felt washer, washer retainer and bearing in the end head. Place the other washer retainer, felt washer and bearing retainer over the bearing and install the attaching screws. Slide the end head on the armature shaft and install the drive key and pulley. Slide the arma¬ ture into place with the hole in the end head over the dowel pin in the generator frame. c. Install Commutator End Plate and Brushes (fig. 89). Place the brush arms and springs over the pins in the end plate. Install the end plate on the frame with the hole in the plate over the dowel pin in the frame and install the frame screws. Install the bearing plate cover and 72 GENERATOR TM55-1146 57-58 gasket. Hold the brush arms out against the spring tension and slide the brushes into the brush holders with the angle on the brushes con¬ forming with the contour of the commutator. Connect the brush pigtails to the brush holders and the lead wires to the brush holder located counterclockwise from the armature post. Be certain that the terminals do not contact the generator frame. Place the head band in position and install the clamp bolt. 58. BENCH TESTS a. Connect Generator and Test Output. After the generator has been assembled, test it on a test bench. Ground the field terminal to the generator frame and run the generator up to a speed of approximately 900 to 950 revolutions per minute and connect the battery to the arma¬ ture terminal. Adjust the speed to obtain ap¬ proximately 12 amperes at 8 volts for the 6-volt generator or 17 amperes at 15 volts for the 12- volt generator, then compare the speeds with the following specifications (subpar. b below). Do not operate the generator at speeds giving an output in excess of the figures given above, as a higher output would cause overheating and pos¬ sible damage to the generator. b. Generator Output (Without Regulator). 6-Volt 4.0 amps, 7.6 volts at 950 rpm 12.0 amps, 7.6 to 8.0 volts at 1350 rpm 12-Volt 4.0 amps, 14.6 volts at 900 rpm 17.0 amps, 14.6 to 15.0 volts at 1250 rpm TM55-1146 59-60 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section XVI GENERATOR REGULATOR Paragraph Description. 59 Regulator tests and adjustments. 60 Bench repairs. 61 59. DESCRIPTION a. Description. The regulator assembly con¬ tains three units, the circuit breaker, the current regulator and the voltage regulator. (1) Circuit Breaker. Used as an auto¬ matic switch which closes the charging circuit between the generator and the battery when the generator is charging and opens the circuit when the generator is not charging, thus preventing the battery discharging back through the gen¬ erator. (2) Current Regulator. Limits the maxi¬ mum ' current output in amperes. When the generator output reaches a predetermined maxi¬ mum, the regulator points open, cutting in a resistance in the generator field circuit and reducing the output. Immediately upon the drop¬ ping of the output, the points close, cutting out the resistance and the output rises. These cycles occur so rapidly that the points vibrate at a high frequency, thus holding the output constant at a predetermined maximum. (3) Voltage Regulator. Used for holding the voltage of the electrical system constant within close limits. When the voltage rises to a predetermined value, the regulator contact points vibrate, thus cutting in and out a resis¬ tance in the generator field circuit. 60. REGULATOR TESTS AND ADJUSTMENTS a. General. (1) Regulator Seals. The regulator assem¬ bly is sealed to indicate that it has had the origi¬ nal factory setting, and to prevent disassembling of the unit except by mechanics authorized to adjust or repair it because precision gages and meters are required to make accurate adjust¬ ments and repairs to the regulator. Do not at¬ tempt to adjust the regulator unless the neces¬ sary equipment required for electrical tests and measurement of the contact point gaps in the regulator are available. (2) Testing Regulator on Test Bench (fig. 90). When testing or adjusting the regu¬ lator on a test bench, mount it firmly and in a place where there is no excessive vibration. Test the regulator on a test bench equipped with a motor driven generator and a fully charged bat¬ tery duplicating the operation of the regulator ARMATURE TERMINAL | BATTERY TERMINAL FIELD TERMINAL GENERATOR REGULATOR GENERATOR 74 GENERATOR REGULATOR TM55-1146 60 when in service. Mount it on the test bench in the same position as when installed. Make con¬ nections between generator and regulator as shown in figure 90. When testing the circuit breaker, connect the voltmeter between regula¬ tor armature terminal marked “A” and ground. For all other tests, connect voltmeter between regulator battery terminal marked “B” and ground. b. Testing and Adjusting Regulator Units. (1) Preheat Regulator. Before attempt¬ ing to make adjustments, heat the regulator by operating it for 15 minutes with the generator charging approximately one half the maximum amperes shown on the nam^ plate of the regu¬ lator or generator. While heating and testing the regulator, leave the cover on the unit, be¬ cause the cover helps retain the heat. When removing and installing the cover exercise care to prevent touching the cover on the circuit breaker which would cause a short circuit and damage the regulator assembly. (2) Clean Contact Points. Inspect the contacts of all three units. In normal use the contacts will become grayed. If the contacts are burned or dirty or if they are not smooth, file them with a No. 6 American Swiss cut equalling file. Move the file parallel and lengthwise to the armature. File just enough so that the contacts present a smooth flat surface toward each other. It is not necessary to remove every trace of burning. After filing, dampen a piece of linen tape in refined carbon tetrachloride and draw the tape between the contacts. Repeat with a dry piece of tape. Use clean tape for each set of contacts. (3) Test Circuit Breaker (End Unit WITH Heavy Winding) . Connect a reliable am¬ meter in series with the regulator terminal marked “B” and the lead removed from the ter¬ minal. Connect an accurate voltmeter from the regulator terminal marked “A” to the regu¬ lator base. Disconnect the field lead from the regulator terminal marked “F” and insert a variable resistance (3 ampere-50 ohm capacity) between the lead and the regulator terminal. Run the engine at about 1200 revolutions per minute. Insert all the resistance in the field cir¬ cuit, then slowly reduce the resistance, noting the voltage reading just before the change caused by the closing of the circuit breaker. In¬ crease the charging rate to the figure specified below for the regulator being tested, then reduce the charging rate by inserting resistance in the field circuit. Note the voltmeter and ammeter reading just before the circuit breaker opens. The closing voltage and opening amperage should be within the following limits: 6-Volt 12-Volt Points close at... 6.4 to 7.0 13.0 to 13.75 volts volts Points open at. .. 4.1 to 4.6 8.2 to 9.3 volts volts after a after a charge of charge of 10 amps. 10 amps. An accurate method for noting the exact in¬ stant of opening or closing of the circuit breaker is to connect a headphone (2000 ohms or higher) to the battery and armature terminals of the regulator. When the contacts open or close a click will be heard in the headphone. (4) Adjust Circuit Breaker (fig. 91). To adjust the closing voltage, change the armature spring tension by bending the hanger at the lower end of the spring. Increase the spring tension to raise the closing voltage or decrease the tension to lower the voltage. To adjust the opening voltage, raise or lower the stationary contact, keeping the contacts perfectly alined. Increasing the contact gap raises the opening voltage. Change the contact gap by expanding or contracting the stationary contact bracket, keeping the contacts alined. Do not adjust the gap between the contacts to less than 0.015 inch. (5) Test Voltage Regulator (End Unit WITH Heavy Winding) . Connect the ammeter as described in step (3) above and connect the voltmeter from the regulator terminal marked ‘‘B” to the regulator base. Remove the variable resistance from the field circuit. Run the gen¬ erator at 10 amperes output for 15 minutes to make sure the regulator is at normal operating temperature. Have the cover on the unit during this warm-up period and when taking readings. Stop the engine, then bring it up to approximate¬ ly 1150 revolutions per minute. Adjust the am¬ perage to 10 amperes output by turning on lights or accessories and then note the voltmeter read¬ ing which should be as follows: 6-volt regulator... . 7.1 to 7.3 volts 12-volt regulator.... 14.3 to 14.6 volts NOTE: In hot climates (consistently above 95°F.) the voltage regulator 75 TM55-1146 60-61 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 may he set at a lower limit. For ex¬ ample, at a temperature of 120° F. the 6-volt regulator may he set at 6.9 volts or the 12-volt regulator may he set at 14.2 volts. However, there must always he at least 0.5 volt more voltage at which the regulator unit operates than the voltage at which the circuit hreaker closes. See paragraph 21 e for battery electrolyte specifications. (6) Adjust Voltage Regulator (%. 91). To adjust the voltage regulator, increase or de¬ crease the armature spring tension. Increasing the spring tension increases its operating volt¬ age. This is done by bending the hanger at the lower end of the spring. Replace the cover after making each adjustment to maintain heat and take a final reading. In order to obtain an accu¬ rate indication of the operation of the voltage regulator unit connect a headphone (2000 ohms or higher) between the terminal marked “F” and ground to pick up the sound of the opening and closing of the contacts. The clicks should be regular and clear without irregularities or missing. If the tone is not clear and regular re¬ move the regulator cover and inspect the con¬ tacts. The contacts should be flat and not burned excessively and should be alined to make full face contact. If the contacts need cleaning see step (2) above. (7) Test Current Regulator (Center Unit) . Connect the regulator and instruments as described in step (5) above and run the engine at approximately 2000 revolutions per minute. Turn on lights and accessories so that the gen¬ erator must charge at its maximum rate, and take voltage readings at “B” regulator terminal: 6-volt regulator, 11.0 to 13.0 amperes at approx. 7.0 volts. 12-volt regulator, 16.0 to 18.0 amperes at approx. 14.0 volts. (8) Adjust Current Regulator (fig. 91). To increase the operating amperage, increase the armature spring tension by bending the hanger at the lower end of the armature spring. After each adjustment stop the engine, then restart it. Bring the engine up to speed and take an am¬ meter reading. Have the cover on the unit when taking reading and use headphone as outlined in step (6) above. If the tone is not clear and regu¬ lar, remove the regulator cover and inspect the contacts. The contacts should be flat and not burned excessively and should be alined to make full face contact. If the contacts need cleaning- see step (2) above. (9) Recheck Adjustments. If adjust¬ ments are made to any of the regulator units, operate the generator at 10 amperes output for five minutes with the cover on the regulator and repeat the testing procedure for all units as cov¬ ered in steps (3) through (8) above. CIRCUIT CURRENT REGULATOR VOLTAGE REGULATOR BEND SPRING HANGERS TO ADJUST SPRING TENSION 32X133 Figure 91—Regulator Adjusting Hangers 61. BENCH REPAIRS a. General. The regulator may bQ tested and repaired by mechanics thoroughly trained in the servicing of electrical equipment with precision meters and gages. Do not attempt to repair the regulator unless the proper tool equipment is avaliable because accurate adjustments of regu¬ lator air gaps, contact point gaps and spring tension are very important. b. Visual Inspection. After removing the cover of the regulator and before making any tests or adjustments, make a close visual inspec¬ tion of the regulator, giving special attention to the following items: (1) Evidence of burning or abnormal high temperature at the coils, contacts, insulation, contact springs, external terminals or any other point. It is recommended that this test be made with a magnifying glass. (2) Loose connections which result from poor soldering. (3) Loose nuts on bottom of the magnet 76 GENERATOR REGULATOR TM55-1146 61 cores, loose rivets or screws. All nuts and screws must have lock washers. (4) Loose contacts. (5) Misalinement of contacts. (6) Armature stop rubbing against or inter¬ fering with the circuit breaker armature. (7) Bent armature either at the contact or hinge end. The armature should be perfectly straight from one end to the other’ (8) Bent field yoke. (9) Bent or distorted armature hinges. (10) Reversed bi-metal hinges on the circuit breaker unit. When correctly installed the brass side must be up. (11) Stripped or crossed threads on any screw or nut. (12) Corrosion due to salt or acid. (13) Evidence of water having been inside of cover. (14) Incorrect, bent or distorted armature springs. In case of doubt, replace the spring. (15) Broken or altered carbon resistor. (16) Broken gaskets. (17) Incorrect wiring connections between units. (18) Reversed armature springs. On regu¬ lators using different armature springs for the separate units, the size spring is specified in paragraph 2 a. (19) Important: When disassembling a regulator, watch closely the locations of all in¬ sulators and assemble them in their proper position. c. Clean Contact Points. See paragraph 60 b(2). d. Check Carbon Resistor (fig. 92). Test the resistance of the carbon resistor with an accu¬ rate ohmmeter. The resistor is located on the under side of the regulator base. The resistance of the carbon resistor is as follows: 6-volt regulator.... 28.0 to 32.0 ohms (marked 30) 12-volt regulator.... 57.0 to 63.0 ohms (marked 60) LEADS TO OHMMETER 32X134 Figure 92—Testing Carbon Resistor e. Test Voltage Windings. (1) Circuit Breaker Shunt Coil (fig. 93). Unsolder the fine lead wire from the voltage regu¬ lator winding where it is connected to the circuit breaker yoke. With an ohmmeter, measure the resistance from the regulator terminal marked “A” to the regulator base. Replace the circuit breaker unit if the resistance is not within the following limits: 6-volt regulator. . 29.8 to 33.0 ohms 12-volt regulator. . 111.0 to 125.0 ohms (2) Voltage Regulator Coil (fig. 94). Measure the resistance from the regulator base to the lead unsoldered from the circuit breaker LEADS TO OHMMETER 32X136 Figure 93—Testing Resistance of Circuit Breaker Shunt Coil Winding • 77 TM55-1146 61 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 yoke. Replace the voltage regulator unit if the resistance is not w ithin the following limits: 6-volt regulator.... 10.8 to 12.0 ohms 12-volt regulator... . 43.7 to 49.3 ohms 32X137 Figure 94—Testing Resistance of Voltage Regulator Coil Winding f. Check Armature Air Gaps. Check the armature air gap of all three units of the regu¬ lator assembly. Air gap specifications are as follows: 6-Voll and 12-Volt Regulators Circuit breaker.0.031 to 0.034 in. Voltage regulator.. . .0.048 to 0.052 in. Current regulator. . . .0.048 to 0.052 in. 32X138 Figure 95—Measuring Circuit Breaker Armature Air Gap (1) Circuit Breaker (fig. 95). Check the circuit breaker armature air gap with the points open. Use pin gage inserted between the arma¬ ture and the magnetic core as near to the hinge end as possible. Adjust the air gap by bending the armature stop. Make sure the stop does not contact the side of the armature. (2) Current and Voltage Regulator (fig, 96). Use pin gage to check armature air gap of both the current and voltage regulators with the points j ust breaking. Take the measurement on the point side of the brass armature stop pin. Connect a test lamp in series with the regulator field terminal marked “F,” the regulator base and a battery. With the low limit pin gage in place, depress the armature and the light should go out or be noticeably dimmed. With the high limit pin in place the lamp should stay lighted. Use two fingers to depress the armature, one on either side of the contact spring, so that the con¬ tact spring is not touched. Do not apply pressure near the center of the armature. To adjust, loosen the screw and raise or lower the armature stop. Tighten the screw securely. Check to see that the springs upon which the movable contacts are mounted are straight and parallel with the armature. PIN GAGE 32X139 Figure 96—Measuring Current or Voltage Regulator Armature Air Gap g. Check Contact Point Gaps (fig. 97). (1) Circuit Breaker. Check the gap of the contact points in the circuit breaker. Thi:5 gap should be 0.015 inch (minimum). The gap will 78 * GENERATOR REGULATOR TM55-1146 61 possibly be more than this in actual adjustment, but should not be wide enough to fail to contact before armature reaches its limit of travel. Ad¬ just by bending the armature stop. (2) Current and Voltage Regulator. Check point gap of both the current and voltage regulator with the armature against the stop pin. The gap should be 0.012 inch (minimum). Hold the armature down with two fingers and do not touch the contact spring. The tolerance of 0.012 inch (minimum) is approximate only; too much variation indicates wrong length of armature stop pin and a new unit will be needed. h. Assembly of Regulator. When all the pre¬ ceding checks and adjustments have been com¬ pleted, connect all leads which have been discon¬ nected either by the removal of a screw or by un¬ soldering. Where resoldering is necessary, see that a good clean contact is made. Do not use acid for soldering flux; use only rosin flux. When 32X140 Figure 97—Measuring Contact Point Gap completely assembled with cover, test and adjust the regulator (par. 60). 79 TM55-1146 62-64 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section XVH IGNITION DISTRIBUTOR Description. Bench tests. Disassembly and inspection. Assembly. 62. DESCRIPTION a. Description. The ignition distributor is driven by a drive shaft which engages the oil pump shaft. The distributor accurately times and distributes the ignition current. A set of breaker points located in the base of the distribu¬ tor times the ignition by making and breaking the primary circuit between the battery and the ignition coil at the correct time. A rotor in the distributor cap distributes the high tension cur¬ rent, built up by the ignition coil, to the spark plugs as the pistons reach the top of their com¬ pression stroke. An automatic governor built into the base of the distributor provides auto¬ matic advance of the ignition timing as the en¬ gine speed is increased. 63. BENCH TESTS a. Test Automatic Advance. Place the dis¬ tributor in a test fixture and check the automatic advance against the specifications given in para¬ graph 2 s. b. Test Cam Angle (Point Dwell). With no excessive play in the distributor shaft bushings and the breaker point gap set at 0.020 inch, test the cam angle on test fixture. If cam angle is less than 371/2 degrees or more than 40 degrees, re¬ place the cam and stop plate. 64. DISASSEMBLY AND INSPECTION a. Remove and Inspect Cap and Rotor. Re¬ move the cap and pull the rotor straight off the distributor shaft. Clean the distributor cap and examine it for cracks, carbon runners or cor¬ roded terminals. If any of these conditions are present, replace the cap. If the vertical faces of the inserts are excessively burned, replace the cap. If the horizontal faces of the inserts are burned, replace the cap and rotor, as this condi¬ tion indicates that the rotor is too short. Inspect the contact plunger and spring. If the plunger is excessively worn or stuck or the spring is worn Paragraph . 62 . 63 . 64 . 65 or damaged, replace the spring and plunger. In¬ spect the rotor for cracks or damage. A slight burning at the end of the rotor metal strip is a normal condition and will not affect the operation of the distributor. If the top of the metal strip is burned, replace the rotor as it is too short. b. Remove Breaker Plate Assembly (fig. 98). Remove the two screws which hold the breaker plate to the distributor base and lift out the breaker plate assembly. DISTRIBUTOR PLATE ATTACHING SCREWS 36x50 Figure 98—Breaker Plate Assembly Removed c. Remove Condenser and Breaker Points. Disconnect the condenser lead wire and remove the mounting screw and condenser. If points are burned or discolored due to heat, replace conden¬ ser and points. Slide the breaker arm off its pivot post. Remove lock nut and screw the breaker point screw out of the bracket. d. Remove Cam and Stop Plate and Check Drive Shaft Bushing Wear (fig. 99). Remove felt wick from top of cam, spread and remove lock spring ring which holds the cam and stop plate to the drive shaft and lift the cam and stop plate and thrust washer off the shaft. Clamp the 80 IGNITION DISTRIBUTOR TM55-1146 64-65 distributor in a holding jig and clamp the jig in a vise. Do not clamp the distributor base in a vise as this might distort the bushings and make it impossible to check bushing wear. At¬ tach a dial indicator to the distributor base and adjust the plunger of the indicator against the top of the drive shaft. Move the top of the shaft to and from the indicator with just enough force to indicate the clearance of the shaft in the bush¬ ings. Too much force will cause the shaft to spring and show a false reading. If the clearance exceeds 0,008 inch, replace the bushings. 32X37 Figure 99—Measuring Drive Shaft Bushing Wear e. Remove Drive Shaft and Bushings. Drive the rivet out of the drive shaft collar at the lower end of the distributor base and push the drive shaft up through the collar and distributor base. Take care not to distort governor springs. If weights are removed, identify the springs so that they can be installed in their original position. Remove the lower thrust washer from the shaft or distributor base. Press the bushings out of the distributor base. 65. ASSEMBLY a. Install Drive Shaft Bushings. Soak new bushings in engine oil for fifteen minutes. Press the upper bushing into the distributor base from the top; line up oil hole with oiler in base. Press lower bushing into base from bottom and ream to shaft size. b. Assemble Governor Weights to Drive Shaft (fig. 100). Each governor weight contains a lubricant chamber about midway of the pivot GOVERNOR LUBRICANT WEIGHTS CHAMBER 32X38 Figure 100—Packing Governor Weight with * Lubricant hole. Be sure the chambers are filled with lubri¬ cant before the weights are assembled. Press the pivot holes full of grease. Install the governor weights over the pivot pins and wipe away the surplus grease which will be forced out the pivot pin holes. Connect the governor weight springs to the weights and the spring brackets in their original position. c. Install Drive Shaft in Distributor Base. If bushings have not been replaced and have been washed in dry-cleaning solvent, lubricate \ them thoroughly. Slide the cup shaped thrust washer on the drive shaft with the concaved side first. Install the shaft through the distributor base, slide the drive shaft thrust washer and thrust collar on the shaft and install a new pin. If a new shaft is installed, use a new thrust collar, and when drilling the pin hole hold the shaft down and the collar up against the base so there will be no end play in the shaft when the pin has been installed. d. Install Cam and Stop Plate. Place the thrust washer over the top end of the drive shaft. Place the cam and stop plate over the end of the shaft and the lugs on the governor weights. Put a drop of oil on each lug. Install the spring lock ring and felt wick at the top of the drive shaft. Put two or three drops of light oil on the felt wick. e. Install Breaker Points and Condenser. Install the lock nut, and screw the breaker point screw through the bracket. Slide the breaker arm over the pivot post with the breaker arm 81 TM55-1146 65 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 spring against the terminal bracket and place the breaker arm spring clip over the spring and bracket. Place the condenser in position and in¬ stall the mounting screw with lock washer. Con¬ nect the condenser lead wire to the terminal bracket with lock washer and screw. f. Install Breaker Plate Assembly. Slide the rubber terminal slot cover over the terminal bracket and place the plate assembly in the dis¬ tributor base. Install the two mounting screws with lock washers. g. Adjust Breaker Points (fig. 101). Rotate the distributor shaft until the breaker arm rub¬ bing block is on a high point of the cam. Adjust the breaker point screw so that the breaker points are open 0.020 of an inch. Hold the adjust¬ ing screw and tighten the screw locjt nut. Re¬ check the adjustment. Figure 101—Breaker Point Adjustment 32X40 Figure 102—^Testing Breaker Arm Spring Tension h. Adjust Breaker Arm Spring Tension (fig. 102). Hook a spring scale on the arm at the point end, and pull at right angles to the point surfaces. Take a reading as the breaker points separate. The spring tension should be 17 to 20 ounces; if not, loosen the screw which holds the end of the breaker point spring and slide the end of the spring in or out as necesary. Do not pull conduc¬ tor ribbon tight against spring, as this will cause ribbon to fatigue and break. Retighten the screw and recheck the tension. i. Install Distributor Rotor and Cap. Place the rotor over the distributor cam so that the flat in the rotor hub registers with the flat on the cam and push the rotor straight into position. Place the cap on the distributor base so that the lip on the counterbore of the cap registers with the notch in the distributor base, and press the two cap springs into the depressions in the cap. LOCK NUT BREAKER POINT SCREW RUBBING BLOCK BREAKER POINT GAP BREAKER ARM ASSEMBLY CAM 36x51 82 STARTING MOTOR TM55-1146 66-67 \ Section XVm STARTING MOTOR Paragraph Description. 66 Disassembly and inspection. 67 Assembly. 68 Tests . 69 66. DESCRIPTION a. Description. The starting motor is mounted on the engine flywheel housing and en¬ gages the flywheel through a pinion to crank the engine. The battery current is supplied to the starting motor through a solenoid switch mounted on top of the starting motor frame. 67. DISASSEMBLY AND INSPECTION a. Remove Solenoid Switch and Clean Start¬ ing Motor. (1) Remove Solenoid Switch. Disconnect the solenoid switch bus bar from the starting motor terminal. Remove the screws which hold the switch assembly to the starting motor frame and remove the switch assembly. (2) Clean Outside of Starter. Clean the outside of the starting motor thoroughly while the head band is still in place. CAUTION: Use a cloth, damp with cleaning solvent. Do not dip the motor in solvent as the solution will enter the unit through the pinion housing and damage the armature and field coils. b. Disassemble (fig. 104). (1) Remove Head Band. Loosen the clamp screw and remove the head band. Do not dam¬ age the felt gasket on the inside of the band. Blow out the dust and dirt from the inside of the motor with compressed air. (2) Test Armature End Play (fig. 103). Attach a dial indicator to the pinion housing with the plunger against the end of the armature shaft and move the shaft endwise in the bush¬ ings to determine the end play. This measure¬ ment should not exceed He inch. If more end play is indicated, replace spacer washers and/or bushings as required when the motor is re¬ paired. (3) Remove Commutator End Plate and Bendix Drive Housing. Clarnp the starting mo- PRY LIGHTLY AGAINST END 35x41 Figure 103—Measuring Starting Motor Armature End Play tor assembly in a vise and remove the two frame screws which hold the assembly together. Make a hook from a piece of wire, raise the brush springs and lift the brushes from the brush hold¬ ers. Loosen the bendix drive housing and pull the housing and armature assembly out of the start¬ ing motor frame. Slide the housing off the arma¬ ture shaft. Loosen and remove the commutator end plate. (4) Remove Bendix Drive. Clamp the ar¬ mature between the padded jaws of a vise and remove the screw nearest the armature windings which holds the bendix drive pinion assembly on the shaft. Slide the assembly off the armature. c. Cleaning. The inside of the starting motor is coated with a corrosion proofing and it should not be removed. Do not soak the armature and field coils or scrub them with a brush. Wipe out the inside of the frame assembly and clean the armature with a cloth, damp with cleaning sol¬ vent and then dry with compressed air. Wash the commutator end plate, pinion housing and ben- 83 TiVl55-1146 67 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 BENDIX DRIVE DRIVING SPRING SCREWS THRUST WASHER HOUSING BUSHING SOLENOID SWITCH -_r HEAD BAND ARMATURE ASSEMBLY I SCREW LOCKS BENDIX DRIVE COMPRESSION SLEEVE FRAME AND FIELD COIL ASSEMBLY BENDIX DRIVE DRIVING SPRING BENDIX DRIVE PINION ASSEMBLY BENDIX DRIVE HOUSING SPACER WASHER FRAME SCREWS COMMUTATOR END PLATE 35x42 Figure 104—Starting Motor Disassembled dix drive pinion assembly and dry thoroughly. d. Inspection and Tests. (1) Inspect Armature. Inspect the arma¬ ture shaft bearing surfaces for wear, scores or damage. Place the armature in “V” blocks and check the eccentricity of the commutator. If the commutator is burned, rough or out-of-round more than 0.003 inch, turn the commutator down. Make sure the cut is parallel with the shaft and do not remove more metal than necessary to produce a smooth surface. The diameter of the commutator is 1.750 inches and should not be reduced to less than 1.650 inches. If the armature shaft bearing surfaces are scored or worn, re¬ place the armature. Make sure the armature windings are tight in the armature slots and soldered properly to the commutator segments. If resoldering is necessary, be sure the solder does not short circuit the segments. (2) Test Armature for Shorts. Place the armature in a growler and hold a strip of steel or piece of hack saw blade on the core parallel to the grooves. Turn on the growler and revolve the armature slowly. If the metal strip becomes mag¬ netized or vibrates the armature is shorted. Re¬ place the armature. (3) Test Armature for Ground (fig. 105). Connect a test light in series with a battery and touch one lead to the commutator bars, one at a time, and the other lead to the armature shaft. TOUCH ONE PROD TO ARMATURE SHAFT AND OTHER PROD TO COMMUTATOR SEGMENTS— IF TEST LAMP LIGHTS THE ARMATURE IS GROUNDED COMMUTATOR SEGMENTS TEST PROD GROWLER STARTER ARMATURE TEST PROD ARMATURE SHAFT GROWLER SWITCH-OFF TEST LAMP SWITCH-ON 32x64 Figure 105—Testing Starting Motor Armature for Grounds Do not touch the brush surfaces of the commu¬ tator or the bearing surface of the shaft as an arc from the circuit would damage the contacting surfaces. If the light burns the armature is grounded. Inspect for trouble, correct if prac¬ tical or replace the armature. (4) Test Bearing Clearance. Clamp the armature between the padded jaws of a vise so that the commutator end plate and bendix drive housing can be placed in position. Slip the bendix drive housing on the shaft and check for side wear in the bushing. If worn, replace the bush- 84 TM55-1146 67 STARTING MOTOR ing. Place the commutator end plate on the shaft and check for wear; if worn replace the end plate assembly. (5) Inspect Brushes and Holders and Measure Brush Spring Tension. Inspect the brush holders for wear or damage. Test the insu¬ lated holders with a light to see if they are grounded (fig. 106). Replace the commutator end plate assembly if the brush holders are grounded. Check the grounded brush holders to see if they are tight. Rivet the holders to the end plate if loose. Compare the brushes with new ones and if worn to exceed one-half their original length, replace them. Place the end plate assem¬ bly on the armature and install a new set of brushes temporarily for tests. Position the brush springs and measure the tension. Hook a spring scale on the spring and pull straight with the brush holder. If the scale indicates less than 42 or more than 53 ounces just as the brush is free on the commutator, bend the spring hangers or replace the springs to obtain proper tension. Make sure the holders are straight with the com¬ mutator so that the brushes will make good contact. TEST PROD ONE PROD TO INSULATED BRUSH HOLDER AND OTHER PROD TO END PLATE- IF TEST LAMP LIGHTS THE BRUSH HOLDER IS GROUNDED INSULATED BRUSH HOLDERS BUSHING TEST PROD STARTER END PLATE GROWLER SWITCH-OFF TEST LAMP SWITCH-ON GROWLER 32x63 Figure 106—Testing Starting Motor Brush Holder (6) Inspect Frame and Test Field Coils (fig. 107). Inspect the motor frame assembly for cracked or damaged housing. Disconnect one end of the equalizer jumper between the field coils and test between the starting motor ter¬ minal and each field coil with the test light. If the light does not burn, the coil being tested is GROWLER MAIN BRUSHES TOUCH MAIN BRUSHES WITH TEST PRODS- IF TEST LAMP DOES NOT LIGHT, THERE IS A BREAK IN THE COIL WIRING GROWLER SWITCH-O TEST LAMP SWITCH-ON TEST PRODS STARTER FRAME AND FIELD COILS TESTING STARTER FIELD COILS FOR OPEN CIRCUIT STARTER FRAME AND FIELD COILS BRUSHES TOUCH ONE PROD TO MAIN BRUSH AND OTHER PROD TO STARTER FRAME- IF TEST LAMP LIGHTS THE COILS ARE GROUNDED GROWLER TEST LAMP SWITCH-ON TEST PRODS GROWLER SWITC -OFF TESTING STARTER FIELD COILS FOR GROUND 32x66 Figure 107—Testing Starting Motor Field Coils open. Replace the coil assembly. Repeat the test from each insulated brush to determine if the brush leads are satisfactory. If the light does not burn, the brush lead is broken or the soldered connection is faulty. Repair or replace as re¬ quired. Test between the insulated brushes and the frame for grounds. If the light burns, inspect for ground and repair or replace the field coils. (7) Remove Field Coils. Mark the field coil pole shoes so that they can be assembled in ex¬ actly the same position to maintain proper air gap between the shoes and the armature core. NOTE: The two extra shoes do not require re¬ moval unless the frame is to be replaced. Remove the large countersunk screw which holds the field coil pole shoe in the frame, remove the nut and insulators from the starting motor terminal and remove the coils with the pole shoes. 85 TM55-1146 67-68 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 (8) Remove Insulated Brushes. If the in¬ sulated brushes require replacement unsolder the brush lead from the field coil ends, unclinch the connectors and remove the brush and lead. (9) Inspect Bendix Drive Pinion Assem¬ bly. Inspect the bendix drive spring for rust, corrosion or breakage. Replace the spring if dam¬ aged. Inspect the bendix gear for damaged teeth and replace the bendix drive assembly if dam¬ aged. Operate the bendix gear on the shaft by hand to see if it is free. If not, wash the drive in cleaning fluid and oil with SAE 10 oil; if this fails to free up the drive, replace the drive assembly. (10) Test Solenoid Switch. Remove the cap from the end of the solenoid, connect a test light between the starter side of the solenoid and ground and connect the other large terminal of the solenoid to one side of the battery with case connected to the other side of battery. Push the plunger and if the light does not burn, replace the solenoid switch assembly. Connect one bat¬ tery lead to the small terminal on the solenoid and touch the other lead to the housing. If the solenoid shaft does not click in when current is applied, replace the unit. 68. ASSEMBLY a. Install Field Coil Assembly and Brushes. (1) I NSTALL Field Coils. Place the field pole shoes in the field coils so that they will fit in the frame in exactly the same position as when re¬ moved. Slide the assembly into the frame with the insulators on the terminal post. Enter the post in the hole in the frame and start the field pole shoe screws. Tighten the pole screws while striking the frame with a soft hammer to seat the shoes and then stake the screws to the frame. Install the insulators, washer, plain washer and nut on the terminal post. (2) Install Brushes. Crimp the insulated brush leads into the end of the coil leads and solder the connection with rosin core solder. Do not use acid flux. Connect the ground brush leads to the frame with the countersunk screws and make sure that the brush lead terminals make good connection. b. Install Armature, Bendix Drive Pinion Assembly and Bendix Drive Housing. (1) Install Bendix Drive Pinion Assem¬ bly. Place the woodruff key in the armature shaft and slide the bendix drive compression sleeve on the key. Place the bendix drive pinion assembly on the shaft, aline the spring lug with the hole in the compression sleeve and shaft and install the screw. (2) Install Armature and Bendix Drive Housing. Install the thrust washer on the drive end of the armature shaft, lubricate the bendix drive housing bushing and place the housing on the shaft. Clamp the frame and field coil assem¬ bly in the vise, slide the armature into the frame with the commutator toward the brushes and aline the bendix drive housing on the frame dowel. Install the spacer washer on the commu¬ tator end of the armature shaft against the com¬ mutator bars and install the thrust washer against the spacer. Make sure the oiler felt is in position in the commutator end plate and in¬ stall the end plate on the shaft. Aline the plate with the frame dowel and install the two frame screws. Tighten the screws while tapping the end housings with a soft hammer to seat them properly. (3) Install Brushes in Holders. Raise the brush springs and install the brushes in the holders. Be sure that the insulated brushes are in the insulated brush holders and the ground brushes are in the grounded holders. Slide the brushes up. and down in the holders to make sure that they are free. Position the springs on the brush and check the brush leads to see that they do not interfere with the*armature. c. Install Head Band and Solenoid Switch. (1) Install Head Band. Place the head band in position over the inspection holes in the frame. Make sure that the felt gasket is in place and properly seals the inspection holes. Tighten the clamp screw. (2) Install Solenoid Switch. Mount the solenoid switch on the starting motor frame with the cap toward the bendix drive housing and se¬ cure with brass screws. Make sure the contact with the frame of the motor is clean. Connect the bus bar between one switch terminal and the starting motor terminal and attach the cadmium plated lock washers and brass nuts. The solenoid switch terminals and motor terminal must be cadmium plated and equipped with brass nuts. The bus bar must be plated. This is part of the corrosion proof treatment to avoid failure. 86 STARTING MOTOR TM55-1146 69 - 69. TESTS a. Free Running Test. Mount the starter on a test bench equipped with a fully charged bat¬ tery, an accurate voltmeter and ammeter, a vari¬ able load resistor and a tachometer. Connect the negative (—) battery lead to the starting motor terminal and ground the positive terminal to the starting motor frame. Do not connect through the solenoid switch. The ammeter must be in series with the negative battery lead, the volt¬ meter in parallel and the load resistor must be across the battery terminals. Close the test bench battery switch and allow the starting mo¬ tor to run a few seconds to properly seat the brushes, then adjust the load resistor to obtain a reading of 5.5 volts on 6-volt starting motor. The ammeter should indicate 65 amperes at 4900 revolutions per minute. Adjust the load resistor to obtain a reading of 11 volts on 12-volt starter. The ammeter should indicate 30 am¬ peres at 5300 revolutions per minute. Observe the action of the bendix gear to see if it moves freely along the shaft when the starting motor is started and stopped. b. Stall Torque Test. If the test bench is equipped to test the stall torque, connect the torque arm and spring seal to the starting motor and test for stall torque. Multiply the spring scale reading by the length of the torque arm to obtain torque in foot pounds. The proper speci¬ fications are as follows: 6-Volt 12-Volt Voltage . 3.0 volts 6.0 volts Amperage draw. 610 amps 285 amps Torque. 11.5 ft lbs 13.2 ft lbs 87 TM55-1146 70-71 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 Section XIX REVERSE GEAR AND REDUCTION GEAR Paragraph Description. '<^0 Disassembly and inspection. 71 Assembly. 72 Straight drive reverse gear. 73 70. DESCRIPTION a. Reverse Gear and Clutch. The reverse < gear and clutch assembly is mounted in a case at the end of the engine. The reverse gear is of the planetary type. Reversing is accomplished by means of a lined iron band contracting on a drum. An automatic take-up and external adjust¬ ment is provided. The clutch is of the disk type with bronze and steel plates. Adjustment can be made with the cover removed from the reverse gear case (fig. 108). See paragraph 24. b. Reduction Gears. Reduction gears (fig. 108) of different ratios are available. The reduc¬ tion gear assemblies are of internal gear and pinion design. The hardened steel gears with helical teeth are mounted on large ball bearings. The reduction gear assembly is pressure lubri¬ cated by oil from the engine crankshaft. The internal gear acts as a pump and returns the oil to the engine crankcase. 71. DISASSEMBLY AND INSPECTION a. Remove Reverse Gear and Reduction Gear Pinion Assembly. (1) Remove Reverse Gear Fork Shaft (fig. 108). Remove the cover from the case. Re¬ move the clevis pin and the reverse gear band operating lever. Remove the plunger and oil seal from the housing. Remove the fork shaft oil seal retainer attaching cap screws. Remove the clamp screws from the reverse gear fork. Drift the shaft out of the fork and case. LEVER FULCRUM PIN CASE COVER GASKET PLUNGER OIL SEAL BAND OPERATING LEVER REVERSE GEAR FORK REVERSE GEAR FORK SHAFT REVERSE GEAR BAND ADJUSTING ROD PLUNGER PLUNGER SPRING SHAFT OIL SEAL RETAINER ' 36x52 Figure 108—Reverse Gear Fork Shaft Removed REDUCTION GEAR DRIVEN SHAFT HOUSING REDUCTION AND REVERSE GEAR CASE REVERSE GEAR BAND REVERSE GEAR DRUM REDUCTION GEAR PINION BEARING RETAINER 36x53 Figure 109—Reverse Gear Drum and Reduction Gear Pinion Assembly and Band Removed 88 TM55-1146 71 REVERSE GEAR AND REDUCTION GEAR REVERSE GEAR PINIONS REDUCTION GEAR PINION REAR BEARING RETAINER REDUCTION GEAR PINION REVERSE GEAR DRUM REVERSE GEAR PINION BUSHINGS REVERSE GEAR DRUM FRONT COVER REVERSE GEAR DRUM FRONT COVER BUSHING 36x54 REVERSE GEAR PINION SHAFTS REVERSE GEAR PINION THRUST PLATE Figure 110—Reverse Pinions and Bearings Removed (2) Remove Reverse Gear Drum and Band (fig. 109) . Remove the cap screws which attach the reduction gear pinion bearing re¬ tainer to the case and slide the assembly out the front of the case. Remove the adjusting rod and anchor pins and remove the reverse gear band. b. Disassemble Reverse Gear. (1) Remove Pinions and Bearings (fig. 110) . Mark the reverse gear front cover and the drum so that the cover can be installed in its original position. Remove the attaching cap screws and slide the cover straight off the pinion shafts. Slide the pinions off the pinion shafts and press the bushings from the pinions. (2) Remove Reduction Gear Pinion and Clutch (fig. 111). Remove the nut from the front end of the pinion shaft. Press the pinion shaft out of the reverse gear driven gear and the clutch hub. Remove the clutch back plate lock and unscrew the plate from the drum. Remove the three pressure pins from the back plate and remove the clutch plates. Slide the clutch hub from the drum. Drift the clutch hub bushings from the drum. If the reduction gear pinion or rear bearing is to be replaced, remove the large nut and press the pinion shaft out of the bearing. (3) Clean and Inspect Parts. Wash all parts in dry-cleaning solvent. Inspect the pin¬ ions, pinion shafts and roller bearings and re¬ place any parts that are worn or damaged. In¬ spect the gears, ball bearings and shaft and replace if worn or damaged. Examine each clutch plate and if scored, sprung or damaged, replace the part. If the clutch release bearing is CLUTCH BACK PLATE CLUTCH PRESSURE PLATE CLUTCH DRIVEN PLATES REDUCTION GEAR PINION REDUCTION GEAR PINION BEARING BEARING RETAINER CLUTCH BACK PLATE LOCK, SCREW AND LOCKWASHER CLUTCH DRIVING PLATES CLUTCH THRUST PLATE REVERSE GEAR DRUM BUSHINGS REVERSE GEAR CLUTCH HUB REVERSE GEAR DRIVE GEAR BUSHING NUT WASHER REVERSE GEAR DRIVEN GEAR REVERSE GEAR DRUM 36x55 Figure 111—Clutch Disassembled 89 TM55-1146 71-72 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 rough or damaged, replace the clutch spool as¬ sembly. Remove the toggle arm pins and if the pins are worn or the holes in the toggle arms have become elongated, replace the arms and pins. Inspect the reverse gear drum and band. Replace the drum if scored or damaged. Replace the band lining if wear is evident. c. Remove Reduction Gear Driven Shaft Assembly. Mark the reduction gear housing flange in relation to the case so that the assembly can be installed in its original position. Remove the cap screws from the flange and slide the assembly out of the case. d. Disassemble Reduction Gear Driven Shaft. (1) Remove Internal Gear and Shaft (fig. 112). Remove the driven shaft flange nut, washer and metal gasket. Pull the flange off the shaft. Remove the rear bearing retainer and press the oil seal out of the retainer. Press the driven shaft and gear out of the rear bearing and housing. Remove the bearing spacer from the shaft. (2) Remove Bearings and Gear (fig. 112). Tap the rear bearing out of the housing. Insert , a 5/16-inch drift through the holes inside the internal gear and drift the front bearing off the shaft. Remove the cap screws and locks and tap the internal gear off the shaft. (3) Clean and Inspect Parts. Wash all parts in dry-cleaning solvent and inspect the gear and bearings. Inspect the oil seal and sur¬ face of the flange where the oil seal contacts. Replace the seal, the flange or both, if worn. 72. ASSEMBLY a. Assemble Reduction Gear Driven Shaft. (1) Install Internal Gear AND Bearings * (fig. 112). Place the internal gear over the flange on the shaft and install the locks and cap screws. (2) Install Shaft and Bearings (fig. 112). Install the front bearing on the shaft with the trade mark toward the gear. Slide the bear¬ ing spacer over the shaft with the flat end against the bearing. Install the rear bearing in the housing with the trade mark toward, the housing. Install the shaft in the housing and through the rear bearing. (3) Install Oil Seal Retainer and Driven Shaft Flange (fig. 112).' Press a new oil seal in the seal retainer and install the retain¬ er and gasket. Install the drive shaft flange on the shaft and install the metal gasket, washer, nut and cotter pin. b. Install Reduction Gear Driven Shaft (fig, 112). Measure the inside diameter of internal gear and record the measurement for use in checking gear backlash (subpar. h below), Place a new gasket on the flange of reduction gear housing and slide the assembly into the case in its original position. c. Assemble Reverse Gear. (1) Install Clutch (fig. 111). Be sure all parts are clean. Oil the bushings and coat the clutch plates with oil. Install the drum, if re¬ moved, and place the hub in the drum. Install the plain brass thrust plate in the drum with the holes over the ends of the pinion shafts. Install DRIVEN SHAFT FLANGE REAR BEARING OIL SEAL SHAFT NUT, WASHER AND GASKET DRIVEN SHAFT , REAR BEARING BEARING SPACER DRIVEN GEAR FRONT BEARING REAR REDUCTION BEARING GEAR DRIVEN RETAINER SHAFT HOUSING REDUCTION GEAR INTERNAL GEAR DRIVEN SHAFT 36 X 56 Figure 112—Reduction Gear Driven Shaft Disassembled 90 TM55-1146 72-73 REVERSE GEAR AND* REDUCTION GEAR first a steel clutch plate over the teeth of the clutch hub, then a brass plate in mesh with the drum and continue until four steel and four brass plates have been installed. Install the steel clutch pressure plate. Place the three pressure pins in the clutch back plate and screw the back plate into the drum until it is flush with the edge of the drum. Install the back plate lock and cap screw. (2) Install Reduction Gear Pinion (fig. 111). If a new pinion or bearing is being in¬ stalled, press the bearing, trade mark first, against the pinion. Install the pinion bearing lock and nut. Place the pinion bearing retainer over the shaft. Slide the pinion shaft through the clutch spool and clutch hub and press the re¬ verse gear driven gear on the shaft with the long¬ est projection end of the hub toward the drum. Install the retaining washer and nut. Slide the drive gear bushing over the gear hub. (3) Install Reverse Gear Pinions and Bearings. Coat the pinion bushings with oil and press the bushings in the pinions. Slide the pin¬ ions on the shafts. Place the pinion thrust plates over the ends of the pinion shaft with the oil grooves toward the pinions. Install the drum front cover in its original position. d. Install Reverse Drum Band (fig. 109). Place the band in position in the reverse gear case and install the anchor pins with cotter pins. If the band has been relined, loosen the adjust¬ ment rod nuts to allow the band to center in the case when the drum is installed. e. Install Reverse Gear Assembly (fig. 109). Slide the reverse gear assembly into the case and through the reverse band. Enter the reduction gear pinion bearing in the rear of the case. Place the bearing retainer over the bearing with the notches in the retainer registering with the oil holes cast in the case and install the attaching screws. f. Install Reverse Gear Fork and Shaft (fig. 108). Turn the clutch release bearing so that the offset in the pins is up. Place the fork in position * on the pins so that the clamp screws can be in¬ stalled from the front. Adjust the fork keys in the fork shaft so they will enter the keyways and slide the shaft into place. Aline the grooves in the shaft with the clamp screw holes in the fork and install the clamp screws. Install the oil seal retainer cap screws. g. Install Reverse Band Operating Plunger and Lever (fig. 108). Place the plunger oil seal in the reverse gear case. Slide the plunger spring over the plunger and insert the plunger through the seal and into the case. Back off the adjusting set screw in the lever and place the lever in posi¬ tion. Install the clevis pin with a cotter pin. h. Measure Gear Backlash. After installing the reverse and reduction gear assembly on the engine, attach a bar to the driven shaft flange as shown in figure 113. Attach a dial indicator to the case so the indicator plunger will contact the bar at a distance from the center of the hub equal to one-half the inside diameter of the internal gear. Hold the pinion shaft so that it will not turn and rock the flange, with just enough force to indicate the backlash on the dial. If the back¬ lash is less than 0.008 inch or greater than 0.010 inch, adjust the backlash (subpar. i below). Figure 113—Measuring Reduction Gear Backlash i. Adjust Gear Backlash. When the reduction gear driven shaft housing is installed in the case with the cast “X” down, the gears will have maximum backlash. To reduce the backlash, re¬ move the housing attaching cap screws and rotate the housing in the case one or two flange holes. Install the cap screws and recheck the backlash. Repeat the operation if necessary until a backlash of 0.008 to 0.010 inch is estab¬ lished. Install the reverse gear case cover. 73. STRAIGHT DRIVE REVERSE GEAR a. General. The design and construction of the reverse gear used with straight drive instal¬ lation is identical to the reverse gear used with 91 TM55-1146 73 ENGINE, GASOLINE, MARINE, CHRYSLER CROWN, MODEL M7 reduction gears, the case and the tail shaft (fig. 114). On the straight drive reverse gear, the tail shaft carries the propeller shaft companion flange instead of the reduction gear drive pinion. Servicing procedures differ only in the removal and installation of the reverse gear drum assem¬ bly. b. Removal of Straight Drive Reverse Gear Drum Assembly. (1) Remove Reverse Gear Fork Shaft (par. 71 a (1)). THRUST BEARING STOP RING THRUST BEARING OIL SEAL ASS'Y REVERSE GEAR CASE REVERSE GEAR THRUST BEARING THRUST BEARING retainer gasket THRUST BEARING RETAINER THRUST BEARING RETAINER SCREW AND LOCKWASHER TAIL SHAFT FLANGE NUT TAIL SHAFT FLANGE NUT WASHER TAIL SHAFT FLANGE NUT WASHER GASKET REVERSE GEAR TAIL SHAFT FLANGE 36x57 9 Figure 114—Rear End of Straight Drive Reverse Gear Case (2) Remove Reverse Gear Drum and Band. Remove the tail shaft flange nut and pull the flange frbm the shaft. Remove the bearing retainer and press the oil seal assembly from the retainer. Move the drum and shaft out the front of the case. Drift the ball bearing out the rear of the case. Remove the adjusting rod and an¬ chor pins and remove the reverse band. c. Installation of Straight Drive Reverse Gear Drum Assembly. (1) Install Reverse Gear Drum Band (par. 71 a (2)). (2) Install Reverse Gear Drum Assem¬ bly. Slide the assembly into the case and through the reverse band. Place the thrust bearing stop ring against the shoulder on the shaft. Drift the thrust bearing on the shaft and into the case. Press the oil seal assembly in the bearing re¬ tainer and install the retainer. Install the tail shaft flange with metal washer, gasket, plain washer and nut. Tighten the nut securely and install a cotter pin. (3) Install Reverse Gear Fork Shaft (par. 72 f and g). 92 INDEX Page No. Adjustments: breaker arm spring tension. 82 breaker points. 38, 82 carburetor float level. 61 carburetor fuel mixture. 37 engine. 36 generator regulator. 74 ignition timing. 38 reverse gear. 39 spark plugs. 38 valve tappets. 37 Air silencer and flame arrester. 24 Armature: generator (6-volt). 70 generator (12-volt). 72 starting motor. 84 B Battery service. 37 Bearings, camshaft (See “Camshaft and bearings”) Bearings, connecting rod (See “Connect¬ ing rod bearings”) Bearings, crankshaft (See “Crankshaft (main) bearings”) Breaker arm spring tension. 82 Breaker points, adjustment. 38, 82 c Camshaft and bearings: clearance. 44 inspection . 44,47 installation. 52 removal. 45 Carburetor: adjustments. 37 assembling . 59 data. 12 description . 56 disassembling. 56 float level. 61 inspection. 56 installation. 55 rebuilding. 56 removal. 43 Charging circuit, testing for voltage loss 34 Circuit breaker, testing and adjusting... 75 Cleaning of engine parts. 46 Page No. Clearances: camshaft bearings. 44 connecting rod bearings. 40, 53 crankshaft (main) bearings. 41,52 crankshaft end play. 47 piston. 50 timing gear backlash. 44 valve tappets. 37 Compression, testing. 36 Connecting rod bearings: clearance. 40, 53 installation. 41, 53 removal. 40 Connecting rod and piston assembly: assembling . 50 inspection . 49 installation . 41, 53 removal. 41, 44 Contact points: distributor breaker. 38 generator regulator. 75 Cooling system: description . 9 troubleshooting. 31 Core hole plugs, replacement. 47 Crankshaft: end play. 47 inspection . 47 Crankshaft (main) bearings: clearance. 41, 52 installation. 41, 52 removal. 41, 44 Current regulator, testing and adjusting 76 Cylinder block, inspection. 46 Cylinder head and gasket: inspection. 46 installation. 40, 54 removal. 40, 43 D Data: carburetor. 12 distributor . 13 engine . 10 fuel pump. 12 generator and regulator. 12,13 oil pump. 12 reverse and reduction gear. 14 spark plugs. 14 starting motor. 14 water pump. 12 93 INDEX, Cont'd Page No. Description: camshaft and bearings. 5 carburetor. 56 connecting rods and bearings. 5 cooling system. 9 crankcase ventilation. 9 crankshaft and main bearings. 5 cylinder block and head. 5 engine lubrication. 5 fuel pump. 62 generator . 69 generator regulator. 74 oil pump. 67 pistons, pins and rings. 5 * starting motor. 83 valves . 5 water pump. 64 Distributor: adjustments . 38, 82 assembling . 81 breaker arm spring tension. 82 data. 13 description . 80 disassembling. 80 inspection . 80 installation. 54 lubrication . 29 removal. 43 tests. 80 trouble shooting. 33 Distributor breaker points. 38, 82 £ Engine: assembling . 52 data. 10 description . 5 disassembling. 43 inspection of parts. 46 installation. 46 oil recommendations. 24 tests and adjustments. 36 trouble shooting. 30 F Field coils: generator (6-volt) . 70 generator (12-volt) . 72 starting motor. 85 Flame arrester and air silencer. 24 Page No. Flywheel: installation. 53 removal. 43 Fuel pump: assembling . 62 data . 12 description . 62 disassembling. 62 inspection. 62 installation . 55 rebuilding. 62 removal. 43 test . 38 G Gasket, cylinder head. 40 Generator: assembling (6-volt). 70 assembling (12-volt). 72 data . 12 description . 69 disassembling (6-volt) . 69 disassembling (12-volt) . 71 inspection (6-volt). 69 inspection (12-volt). 71 installation. 54 lubrication . 29 removal. 43 tests. 72 trouble shooting. 34 Generator regulator: data . 13 description . 74 tests, adjustments and repairs. 74 trouble shooting. 34 I Identification.of engine. 3 Inspections: camshaft and bearings. 44, 47 carburetor. 56 connecting rod bearings and journals. . 47 connecting rods. 49 core hole plugs. 47 crankshaft, bearings and journals.... 47 cylinder block and head. 46 cylinder bores. 47 engine parts. 46 generator (6-volt). 69 generator (12-volt) . 71 generator regulator. 76 manifolds . 50 94 INDEX, Cont'd Page No. oil pan. 51 oil pressure relief valve. 46 oil pump. 67 oil strainer. 51 pistons . 49 piston pins . 49 starting motor. 83 tappets .. 47 timing gears. 44 valves and springs. 48, 49 valve seats. 49 valve stem guides. 48 water pump. 64 Installation of engine. 15 Intake and exhaust manifold assembly: assembling . 51 disassembling. 50 installation. 55 L Lubrication . 24 M Manifold assembly and gasket: assembling . 51 disassembling. 50 N Noises: bearing . 32 ping or spark knock. 32 piston. 32 valves . 32 Numbers, engine. 3 o Oil cooler. 27, 43 Oil filters.24, 43, 51 Oiling system.•. 5 Oil pan: inspection. 51 installation . 41, 53 removal. 40, 43 Oil pump: assembling . 68 data. 12 description . 67 disassembling. 67 inspection. 67 installation . 54 Page No. rebuilding. 67 removal. 43 Oil pressure. 23 Oil recommendations. 24 Oil strainer, cleaning and inspection. ... 51 Operation: precautions. 23 preparation for operation. 22 prestarting inspections. 22 starting engine. 22 stopping engine. 23 Overheating . 31 Pistons: fitting . 50 inspection . 49 replacement . 41 Piston and connecting rod: assembling .. 50 disassembling. 49 installation. 41, 53 removal. 41, 44 Piston pins, inspection and fitting. 49, 50 Piston rings: fitting . 50 installation . 50 replacement . 41 Power curve. 10 R Reduction gear (See “Reverse and reduc¬ tion gear assembly”) Regulator, generator: (See “Generator regulator”) Reverse and reduction gear assembly: adjustment. 39 assembling . 90 data . 14 description . 88 disassembling . 88 inspection . 88 installation. 42, 55 removal. 42, 43 trouble shooting. 34 Reverse gear, straight drive (See “Straight drive reverse gear”) Rings, piston (See “Piston rings”) 95 INDEX, Cont'd Page No. Spark plugs: adjustment. 38 data . 14 installation. 55 Specific gravity, battery. 37 Starting motor: assembling . 86 data . 14 description . 83 disassembling.•.. 83 inspection. 83 installation. 55 lubrication . 29 removal. 43 tests. 87 trouble shooting. 33 Starting engine. 22 Stopping engine. 23 Straight drive reverse gear: description . 91 installation. 92 removal. 92 T Tappets, valve (See “Valve tappets”) Tests: after assembling engine. 55 battery . 37 compression . 36 distributor . 80 engine . 36 fuel pump. 38 generator . 72 generator regulator. 74 ignition circuit. 33 starting motor. 87 vacuum . 36 Timing gears: backlash . 44 installation. 53 removal. 44 Timing ignition. 38 Tolerances (See “Data”) Page No. Trouble shooting: cooling system. 31 engine . 30 fuel system. 32 generating system. 34 ignition system. 33 oiling system. 31 reverse and reduction gears. 34 starting svstem. 33 V Vacuum test. 36 Valves: grinding . 49 refacing. 48 replacement . 40 replacement of seats. 49 Valve stem guides: inspection. 48 replacement . 48 Valve springs: installation. 40, 52 removal. 40, 43 Valve tappets: adjustment. 37 inspection. 47 installation. 52 Ventilation, crankcase. 9 Voltage regulator, testing and adjusting 76 W Water pump: assembling . 65 data . 12 description . 64 disassembling. 64 inspection. 64 installation. 55 rebuilding. 64 removal. 43 Water temperatures. 23 Wiring diagrams. 20 96 V' ^ l ^ t ^ K. ► t f I r r f f UNIVERSmr OF ILLINOn-URBANA 3 01 12 055579954