Jeep CJ 1945-1970 Repair Information

Engine

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REMOVAL & INSTALLATION



4-134 Engine
L-HEAD MODEL
  1. Drain the cooling system by opening the drain cocks on the bottom of the radiator and the lower right side of the block.
  2.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Disconnect the battery cables.
  2.  
  3. Remove the upper and lower radiator hoses and the heater hoses.
  4.  
  5. Remove the four bolts securing the fan hub and blades.
  6.  
  7. Remove the four radiator attaching screws and lift out the radiator.
  8.  
  9. Disconnect the fuel line and the windshield wiper hose at the fuel pump.
  10.  
  11. Remove the air cleaner from the carburetor.
  12.  
  13. Disconnect the choke and throttle controls.
  14.  
  15. Disconnect the cables at the starter and remove the starter.
  16.  
  17. Disconnect the generator wires.
  18.  
  19. Disconnect the wires from the coil, oil pressure sender and temperature sender.
  20.  
  21. Disconnect the exhaust pipe from the manifold.
  22.  
  23. Place a jack under the crankshaft pulley, disconnect and remove the two front engine supports, and slightly lower the engine. This will allow access to the two top bolts on the bell housing.
  24.  
  25. Install a lifting sling and shop crane on the engine and take up all slack.
  26.  
  27. Unbolt the engine from the bell housing.
  28.  
  29. Pull the engine forward or roll the vehicle backwards until the clutch clears the bell housing. Then, lift the engine up and out of the vehicle.
  30.  

To install:
  1. Lower the engine into the vehicle. Push the engine backwards until the clutch enters the bell housing.
  2.  
  3. Bolt the engine to the bell housing.
  4.  
  5. Let the engine down, onto the two front supports.
  6.  
  7. Bolt the engine to the supports.
  8.  
  9. Connect the exhaust pipe to the manifold.
  10.  
  11. Connect the wires to the coil, oil pressure sender and temperature sender.
  12.  
  13. Connect the generator wires.
  14.  
  15. Install the starter and connect the cables at the starter.
  16.  
  17. Connect the choke and throttle controls.
  18.  
  19. Install the air cleaner on the carburetor.
  20.  
  21. Connect the fuel line, and the windshield wiper hose at the fuel pump.
  22.  
  23. Install the radiator.
  24.  
  25. Install the four bolts securing the fan hub and blades.
  26.  
  27. Install the upper and lower radiator hoses and the heater hoses.
  28.  
  29. Connect the battery cables.
  30.  
  31. Fill the cooling system.
  32.  

F-HEAD MODEL
  1. Drain the cooling system by opening the drain cocks at the bottom of the radiator and the lower right side of the cylinder block.
  2.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Disconnect the battery at the positive terminal to avoid the possibility of a short circuit.
  2.  
  3. Remove the air cleaner horn from the carburetor and disconnect the breather hose at the oil filler pipe.
  4.  
  5. Disconnect the carburetor choke and throttle controls by loosening the clamp bolts and setscrews.
  6.  
  7. Disconnect the fuel tank-to-fuel pump line at the fuel pump by unscrewing the connecting nut.
  8.  
  9. Plug the fuel line to prevent leakage. Disconnect the windshield wiper vacuum hose at the fuel pump.
  10.  
  11. Remove the radiator stay bar on the CJ3B.
  12.  
  13. Remove the upper and lower radiator hoses. Remove the heater hoses, if so equipped, from the water pump and the rear of the cylinder head.
  14.  
  15. Remove the fan hub and fan blades.
  16.  
  17. Remove the four radiator attaching screws and remove the radiator and shroud as one unit.
  18.  
  19. Remove the starter motor cables and remove the starter motor.
  20.  
  21. Disconnect the wires from the alternator or the generator. Disconnect the ignition primary wire at the ignition coil.
  22.  
  23. Disconnect the oil pressure and temperature sending unit wires at the units.
  24.  
  25. Disconnect the exhaust pipe at the exhaust manifold by removing the stud nuts.
  26.  
  27. Remove the spark plug wires from the cable bracket that is mounted to the rocker arm cover. Remove the cable bracket by removing the stud nuts.
  28.  
  29. Remove the rocker arm cover by removing the attaching stud nuts.
  30.  
  31. Attach a lifting bracket to the engine using the head bolts. Be sure that the bolts selected will hold the engine with the weight balanced. Attach the lifting bracket to a boom hoist, or other lifting device, and take up all of the slack.
  32.  
  33. Remove the two nuts and bolts from each front engine support. Disconnect the engine ground strap. Remove the engine supports. Lower the engine slightly to permit access to the two top bolts on the flywheel housing.
  34.  
  35. Remove the bolts that attach the flywheel housing to the engine.
  36.  
  37. Pull the engine forward, or roll the vehicle backward, until the clutch clears the flywheel housing. Lift the engine from the vehicle.
  38.  

To install:
  1. Lower the engine into the vehicle. Push the engine backwards until the clutch enters the bell housing.
  2.  
  3. Bolt the engine to the bell housing.
  4.  
  5. Let the engine down, onto the two front supports.
  6.  
  7. Bolt the engine to the supports.
  8.  
  9. Install the rocker arm cover.
  10.  
  11. Install the spark plug wires on the cable bracket that is mounted to the rocker arm cover. Install the cable bracket by installing the stud nuts.
  12.  
  13. Connect the exhaust pipe at the exhaust manifold by installing the stud nuts.
  14.  
  15. Connect the oil pressure and temperature sending unit wires at the units.
  16.  
  17. Connect the wires from the alternator or the generator. Connect the ignition primary wire at the ignition coil.
  18.  
  19. Install the starter motor and install the starter motor cables.
  20.  
  21. Install the radiator and shroud as one unit.
  22.  
  23. Install the fan hub and fan blades.
  24.  
  25. Install the upper and lower radiator hoses. Install the heater hoses, if so equipped, on the water pump and the rear of the cylinder head.
  26.  
  27. Install the radiator stay bar on the CJ3B.
  28.  
  29. Connect the windshield wiper vacuum hose at the fuel pump.
  30.  
  31. Connect the fuel tank-to-fuel pump line at the fuel pump.
  32.  
  33. Connect the carburetor choke and throttle controls.
  34.  
  35. Install the air cleaner horn on the carburetor and connect the breather hose at the oil filler pipe.
  36.  
  37. Connect the battery at the positive terminal.
  38.  
  39. Fill the cooling system.
  40.  

6-225 Engine
  1. Remove the hood.
  2.  
  3. Disconnect the battery ground cable from the engine and the battery.
  4.  
  5. Remove the air cleaner.
  6.  
  7. Drain the coolant from the radiator and engine.
  8.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Disconnect the alternator wiring harness from the connector at the regulator.
  2.  
  3. Disconnect the upper and lower radiator hoses from the engine.
  4.  
  5. Remove the right and left radiator support bars.
  6.  
  7. Remove the radiator from the vehicle.
  8.  
  9. Disconnect the engine wiring harnesses from the connectors which are located on the fire wall.
  10.  
  11. Disconnect the battery cable and wiring from the engine starter assembly.
  12.  
  13. Remove the starter assembly from the engine.
  14.  
  15. Disconnect the engine fuel hoses from the fuel lines at the right fame rails.
  16.  
  17. Plug the fuel lines.
  18.  
  19. Disconnect the throttle linkage and the choke cable from the carburetor and remove the cable support bracket that is mounted on the engine.
  20.  
  21. Disconnect the exhaust pipes from the right and left sides of the engine.
  22.  
  23. Place a jack under the transmission and support the weight of the transmission.
  24.  
  25. Remove the bolts that secure the engine to the front motor mounts.
  26.  
  27. Attach a suitable sling to the engine lifting eyes and, using a hoist, lift the engine just enough to support its weight.
  28.  
  29. Remove the bolts that secure the engine to the flywheel housing.
  30.  
  31. Raise the engine slightly and slide the engine forward to remove the transmission main shaft form the clutch plate splines.
  32.  

The engine and the transmission must be raised slightly to release the spline from the clutch plate while sliding the engine forward.

  1. When the engine is free of the transmission shaft, raise the engine and remove it from the vehicle.
  2.  

To install:
  1. Lower the engine into the vehicle.
  2.  
  3. Slide the engine rearward to install the transmission main shaft in the clutch plate splines.
  4.  
  5. Install the bolts that secure the engine to the flywheel housing. Tighten the bolts to 30-40 ft. lbs. (41-54 Nm).
  6.  
  7. Install the bolts that secure the engine to the front motor mounts. Tighten the bolts to 75 ft. lbs. (102 Nm).
  8.  
  9. Connect the exhaust pipes to the right and left sides of the engine.
  10.  
  11. Connect the throttle linkage and the choke cable to the carburetor and Install the cable support bracket that is mounted on the engine.
  12.  
  13. Connect the engine fuel hoses to the fuel lines at the right fame rails.
  14.  
  15. Install the starter assembly on the engine. Tighten the starter-to-block bolts to 30-40 ft. lbs. (41-54 Nm) the bracket bolts to 10-12 ft. lbs. (14-16 Nm).
  16.  
  17. Connect the battery cable and wiring to the engine starter assembly.
  18.  
  19. Connect the engine wiring harnesses to the connectors which are located on the firewall.
  20.  
  21. Install the radiator.
  22.  
  23. Install the right and left radiator support bars.
  24.  
  25. Connect the upper and lower radiator hoses to the engine.
  26.  
  27. Connect the alternator wiring harness to the connector at the regulator.
  28.  
  29. Fill the cooling system.
  30.  
  31. Install the air cleaner.
  32.  
  33. Connect the battery ground cable to the engine and the battery.
  34.  
  35. Install the hood.
  36.  

6-226 Engine
  1. Drain the cooling system.
  2.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Remove the hood.
  2.  
  3. Remove the radiator and heater hoses, and all other cooling system hoses.
  4.  
  5. Remove the radiator.
  6.  
  7. Disconnect the battery.
  8.  
  9. Remove the coolant surge tank.
  10.  
  11. Remove the air cleaner and air cleaner bracket.
  12.  
  13. Remove the rear heater hose support bracket.
  14.  
  15. Remove the vacuum line which runs between the carburetor and distributor.
  16.  
  17. Tag and remove the spark plug wires from the distributor.
  18.  
  19. Remove the coil lead from the distributor.
  20.  
  21. Remove the distributor cap.
  22.  
  23. Rotate the engine so that the No.1 cylinder is at TDC of the compression stroke.
  24.  
  25. Mark the relationship of the rotor and distributor body.
  26.  
  27. Mark the relationship of the distributor body and head.
  28.  
  29. Remove the hold-down clamp.
  30.  
  31. Remove the distributor.
  32.  
  33. Disconnect the choke cable and wire.
  34.  
  35. Disconnect the throttle control wire at the carburetor.
  36.  
  37. Disconnect the accelerator cable at the distributor adapter.
  38.  
  39. Disconnect the fuel line at the carburetor.
  40.  
  41. Remove the carburetor.
  42.  
  43. Remove the oil filler tube by pulling it straight out of the block.
  44.  
  45. Tag the coil wires and disconnect them.
  46.  
  47. Remove the ignition coil.
  48.  
  49. Disconnect the oil filter hoses.
  50.  
  51. Remove the filter and bracket.
  52.  
  53. Disconnect the wire at the temperature sending unit.
  54.  
  55. Disconnect the wires at the starter. Tag them.
  56.  
  57. Remove the generator housing.
  58.  
  59. Remove the generator and bracket.
  60.  
  61. Remove the generator idler pulley and bracket.
  62.  
  63. Remove the fan belt.
  64.  
  65. Remove the fan.
  66.  

Early models used a four-bladed fan. Willys recommended that owners of these vehicles replace the fan with the later six-bladed unit. If the original fan was at tacked with hex nuts and lock washers, the new fan should be installed using elastic stop nuts.

  1. Disconnect the radiator brace at the engine mount and swing it out of the way.
  2.  
  3. Disconnect the vacuum line at the fuel pump.
  4.  
  5. Disconnect the fuel lines at the fuel pump.
  6.  
  7. Disconnect the exhaust pipe at the manifold.
  8.  
  9. Disconnect the transfer case linkage.
  10.  
  11. Disconnect the wire at the oil pressure sending unit.
  12.  
  13. Disconnect the engine ground strap.
  14.  
  15. Disconnect the transmission shift rods at the transmission and secure them out of the way.
  16.  
  17. Disconnect the clutch cable at the cross shaft.
  18.  
  19. Remove the cross shaft.
  20.  
  21. Disconnect the hand brake release spring.
  22.  
  23. Disconnect the hand brake cable and conduit and move it out of the way.
  24.  
  25. Disconnect the front driveshaft at the transfer case and axle.
  26.  
  27. Disconnect the rear driveshaft at the transfer case.
  28.  
  29. Disconnect the speedometer cable at the transfer case.
  30.  
  31. Attach a lifting bracket, using existing head bolts.
  32.  
  33. Take up the weight of the engine with a shop crane.
  34.  
  35. Support the transmission with a jackstand.
  36.  
  37. Remove the front engine mount bolts.
  38.  
  39. Place a floor jack under the rear engine support crossmember.
  40.  
  41. Remove the crossmember attaching bolts.
  42.  
  43. Remove the engine-to-bell housing attaching bolts.
  44.  
  45. Raise the engine slightly to free it from the front mounts.
  46.  
  47. Remove the floor jack.
  48.  
  49. Slide the engine forward to free it from the transmission.
  50.  
  51. Raise the engine clear of the truck.
  52.  
  53. Place the engine on a work stand or dolly. Never let it rest on the oil pan.
  54.  

To install:
  1. Lower the engine into the truck.
  2.  
  3. Slide the engine rearward to engage the transmission.
  4.  
  5. Lower the engine onto the front mounts.
  6.  
  7. Install the engine-to-bell housing attaching bolts. Tighten them to 40 ft. lbs. (54 Nm).
  8.  
  9. Install the crossmember attaching bolts. Tighten them to 30 ft. lbs. (41 Nm).
  10.  
  11. Install the front engine mount bolts. Tighten them to 50 ft. lbs. (68 Nm).
  12.  
  13. Connect the speedometer cable at the transfer case.
  14.  
  15. Connect the front driveshaft at the axle and transfer case.
  16.  
  17. Connect the rear driveshaft at the transfer case.
  18.  
  19. Connect the hand brake cable and conduit.
  20.  
  21. Connect the hand brake release spring.
  22.  
  23. Install the cross shaft.
  24.  
  25. Connect the clutch cable at the cross shaft.
  26.  
  27. Connect the transmission shift rods at the transmission.
  28.  
  29. Adjust the linkage.
  30.  
  31. Connect the engine ground strap.
  32.  
  33. Connect the wire at the oil pressure sending unit.
  34.  
  35. Connect the transfer case linkage.
  36.  
  37. Connect the exhaust pipe at the manifold. Tighten the nuts to 50 ft. lbs. (68 Nm).
  38.  
  39. Connect the vacuum line and fuel lines at the fuel pump.
  40.  
  41. Connect the radiator brace at the engine mount.
  42.  
  43. Install the fan and belt.
  44.  
  45. Adjust the belt.
  46.  
  47. Install the generator idler pulley and bracket.
  48.  
  49. Install the generator and bracket. Tighten the bolts to 25 ft. lbs. (34 Nm).
  50.  
  51. Install the generator housing.
  52.  
  53. Connect the wires at the starter.
  54.  
  55. Connect the wire at the temperature sending unit.
  56.  
  57. Install the filter and bracket.
  58.  
  59. Connect the oil filter hoses.
  60.  
  61. Install the ignition coil.
  62.  
  63. Install the oil filler tube.
  64.  
  65. Install the carburetor.
  66.  
  67. Connect the filet line at the carburetor.
  68.  
  69. Connect the throttle control wire at the carburetor.
  70.  
  71. Connect the accelerator cable at the distributor adapter.
  72.  
  73. Connect the choke cable and wire.
  74.  
  75. Install the distributor, aligning all the matchmarks.
  76.  
  77. Install the distributor cap and connect all the wires.
  78.  
  79. Install the vacuum line which runs between the carburetor and distributor.
  80.  
  81. Install the rear heater hose support bracket.
  82.  
  83. Install the air cleaner and air cleaner bracket.
  84.  
  85. Install the coolant surge tank.
  86.  
  87. Connect the battery.
  88.  
  89. Install the radiator.
  90.  
  91. Install the radiator and heater hoses, and all other cooling system hoses.
  92.  
  93. Install the hood.
  94.  
  95. Fill the cooling system.
  96.  

6-230 Engine
  1. Raise and support the truck on jackstands.
  2.  
  3. Drain the oil from the engine.
  4.  
  5. Remove the oil filter.
  6.  
  7. Drain the coolant.
  8.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Disconnect the hydraulic line at the clutch slave cylinder.
  2.  
  3. Remove the hood.
  4.  
  5. Remove the upper and lower radiator hoses.
  6.  
  7. Disconnect the automatic transmission cooler lines.
  8.  
  9. Remove the heater hoses.
  10.  
  11. Remove the radiator.
  12.  
  13. Disconnect and tag all wires attached to the engine.
  14.  
  15. Disconnect and tag any remaining hoses attached to the engine.
  16.  
  17. Remove the drive belts.
  18.  
  19. Remove the alternator.
  20.  
  21. Remove the fan and spacer.
  22.  
  23. Remove the battery and tray.
  24.  
  25. Unbolt the exhaust pipe from the manifold.
  26.  
  27. Remove the exhaust pipe from the bracket at the clutch housing.
  28.  
  29. Remove the carburetor.
  30.  
  31. Disconnect the fuel line at the frame.
  32.  
  33. Remove the front engine support bolts.
  34.  
  35. Take up the weight of the engine with a shop crane.
  36.  
  37. Remove the transfer case.
  38.  
  39. Remove the transmission.
  40.  
  41. Raise the engine slightly, pull it forward to clear the fire wall and lift it out of the vehicle.
  42.  
  43. Lower the engine into the vehicle and slide it rearward slightly.
  44.  
  45. Install the front engine support bolts. Tighten the engine mount bolts to 25-30 ft. lbs. (34-41 Nm).
  46.  
  47. Install the transmission. Tighten the bell housing-to-engine bolts to 40-50 ft. lbs. (54-68 Nm).
  48.  
  49. Install the transfer case.
  50.  
  51. Remove the shop crane.
  52.  
  53. Connect the fuel line at the frame.
  54.  
  55. Install the carburetor. Tighten the nuts to 146-182 inch lbs. (16-20 Nm).
  56.  
  57. Install the exhaust pipe to the bracket at the clutch housing.
  58.  
  59. Connect the hydraulic line at the clutch slave cylinder.
  60.  
  61. Connect the exhaust pipe to the manifold.
  62.  
  63. Install the battery and tray.
  64.  
  65. Install the fan and spacer.
  66.  
  67. Install the alternator. Tighten mounting bolts to 40-45 ft. lbs. (54-61 Nm) and the adjusting bolt to 146-182 inch lbs. (16-20 Nm).
  68.  
  69. Install the drive belts.
  70.  
  71. Install the radiator.
  72.  
  73. Install the heater hoses.
  74.  
  75. Install the upper and lower radiator hoses.
  76.  
  77. Connect the automatic transmission cooler lines.
  78.  
  79. Connect any remaining hoses to the engine.
  80.  
  81. Connect all wires to the engine.
  82.  
  83. Fill the cooling system.
  84.  
  85. Install the oil filter.
  86.  
  87. Fill the crankcase.
  88.  
  89. Install the hood.
  90.  

 
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