Jeep CJ 1945-1970 Repair Information

Cylinder Head

Print

REMOVAL & INSTALLATION



See Figure 1



Click image to see an enlarged view

Fig. Fig. 1: Check the cylinder head for flatness across the head surface

It is important to note that each engine has its own head bolt tightening sequence and torque. Incorrect tightening procedure may cause head warpage and compression loss. Correct sequence and torque for each engine model is shown in this section.

4-134 Engine
L-HEAD MODEL

See Figures 2 through 17

  1. Remove the spark plugs.
  2.  



Click image to see an enlarged view

Fig. Fig. 2: For added clearance, removal of the crossbrace may be necessary



Click image to see an enlarged view

Fig. Fig. 3: Using a flare nut wrench, loosen ...



Click image to see an enlarged view

Fig. Fig. 4: ... then remove the water temperature sender



Click image to see an enlarged view

Fig. Fig. 5: Remove the heater hoses from the cylinder head



Click image to see an enlarged view

Fig. Fig. 6: Remove the cylinder head nuts retaining the oil filter bracket ...



Click image to see an enlarged view

Fig. Fig. 7: ... then set it aside



Click image to see an enlarged view

Fig. Fig. 8: Make certain to maintain the oil filter in an upright position so that no oil will leak



Click image to see an enlarged view

Fig. Fig. 9: Remove the air filter inlet tube and spark plug wires from the cylinder head



Click image to see an enlarged view

Fig. Fig. 10: It may be easier to remove the distributor cap along with the spark plug wires



Click image to see an enlarged view

Fig. Fig. 11: Remove any remaining cylinder head nuts ...



Click image to see an enlarged view

Fig. Fig. 12: ... then lift the cylinder head off of the engine block



Click image to see an enlarged view

Fig. Fig. 13: Remove the old gasket from the engine block



Click image to see an enlarged view

Fig. Fig. 14: On L-head engines, all valves are mounted in the engine block ...



Click image to see an enlarged view

Fig. Fig. 15: ... and the cylinder head only forms the combustion chambers



Click image to see an enlarged view

Fig. Fig. 16: Make certain to tighten the cylinder head nuts to the proper torque value



Click image to see an enlarged view

Fig. Fig. 17: To prevent cylinder head warpage and to ensure adequate cylinder sealing, it is essential that the cylinder head mounting bolts be tightened in the sequence shown

  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 temperature sending unit.
  2.  
  3. Remove the head nuts.
  4.  
  5. Lift the head from the block.
  6.  

Do not use a sharp instrument such as a chisel or screwdriver to break the head from the block. If the head sticks, screw lifting hooks into the No. 1 and 4 spark plug holes.

  1. Thoroughly clean the gasket mating surfaces. Remove all traces of old gasket material. Remove all carbon deposits from the combustion chambers. Lay a straightedge across the head and check for flatness; total warpage should not exceed 0.001 in. (0.0254mm).
  2.  
  3. Install the head, using a new gasket. Make sure the head and block surfaces are clean. Tighten the head to 60-70 ft. lbs. (82-95 Nm).
  4.  

F-HEAD MODEL

See Figures 18, 19, 20, 21, 22, 23, 24 and 25



Click image to see an enlarged view

Fig. Fig. 18: Remove the oil filter and bracket from the cylinder head



Click image to see an enlarged view

Fig. Fig. 19: Detach the oil filler bracket from the cylinder head



Click image to see an enlarged view

Fig. Fig. 20: If not already done, label and remove the pushrods



Click image to see an enlarged view

Fig. Fig. 21: Remove all cylinder head mounting bolts-one bolt is located in the intake manifold



Click image to see an enlarged view

Fig. Fig. 22: Lift the cylinder head from the engine block ...



Click image to see an enlarged view

Fig. Fig. 23: ... then remove the old gasket from the engine block



Click image to see an enlarged view

Fig. Fig. 24: Use a torque wrench to tighten the cylinder head bolts to the proper value



Click image to see an enlarged view

Fig. Fig. 25: Make certain to tighten the cylinder head bolts in the sequence shown

  1. Drain the coolant.
  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 upper radiator hose.
  2.  
  3. Remove the carburetor.
  4.  
  5. On early engines remove the by-pass hose on the front of the cylinder head.
  6.  
  7. Remove the rocker arm cover.
  8.  
  9. Remove the rocker arm attaching stud nuts and rocker arm shaft assembly.
  10.  
  11. Remove the cylinder head bolts. One of the bolts is located below the carburetor mounting, inside the intake manifold.
  12.  
  13. Lift off the cylinder head.
  14.  
  15. Thoroughly clean the gasket mating surfaces. Remove all traces of old gasket material. Remove all carbon deposits from the combustion chambers. Lay a straightedge across the head and check for flatness. Total deviation should not exceed 0.001 in. (0.0254mm).
  16.  
  17. Reverse the procedure to install the cylinder head. Tighten the head bolts first to 40 ft. lbs. (54 Nm), then to the specified torque in the correct sequence.
  18.  

6-225 Engine

See Figure 26



Click image to see an enlarged view

Fig. Fig. 26: Make certain to tighten the cylinder head mounting bolts in the sequence shown to ensure proper cylinder sealing and to prevent damage to the cylinder head

  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 intake manifold.
  2.  
  3. Remove the rocker cover.
  4.  
  5. Remove the exhaust pipes at the flanges.
  6.  
  7. Remove the alternator in order to remove the right head.
  8.  
  9. Remove the dipstick and power steering pump, if so equipped, in order to remove the left head.
  10.  
  11. Remove the valve cover and the rocker assemblies. Mark these parts so that they can be reinstalled in exactly the same positions.
  12.  
  13. Unbolt the head bolts and lift off the cylinder head(s). It is very important that the inside of the engine be protected from dirt. The hydraulic lifters are particularly susceptible to being damaged by dirt.
  14.  

To install:
  1. Thoroughly clean the gasket mating surfaces. Remove all traces of old gasket material. Remove all carbon deposits from the combustion chambers. Lay a straightedge across the head and check for flatness. Total deviation should not exceed 0.001 in. (0.0254mm).
  2.  
  3. Do not apply sealant to the head or block. Coat both sides of the gasket with sealer. The gasket should be stamped TOP for installation. Place the gasket on the block.
  4.  
  5. Install the head on the block. Insert the bolts and tighten them, in sequence, to the 65-85 ft. lbs. (88-116 Nm), in three progressive passes.
  6.  
  7. Install the rocker assemblies and the valve covers. Tighten the rocker arm assemblies to 25-35 ft. lbs. (34-48 Nm) and the valve covers to 36-60 inch lbs. (4.0-6.7 Nm).
  8.  
  9. Install the dipstick and power steering pump, if so equipped.
  10.  
  11. Install the alternator. Tighten the bracket-to-head bolts to 30-40 ft. lbs. (41-54 Nm), the bracket to water pump bolts to 15-25 ft. lbs. (20-34 Nm).
  12.  
  13. Install the exhaust pipes at the flanges. Tighten the nuts to 20 ft. lbs. (27 Nm).
  14.  
  15. Install the intake manifold. Tighten the bolts to 45-55 ft. lbs. (61-75 Nm).
  16.  
  17. Fill the cooling system.
  18.  

6-226 Engine

See Figure 27



Click image to see an enlarged view

Fig. Fig. 27: Tighten the cylinder head mounting bolts only in the sequence shown

  1. Remove the hood.
  2.  
  3. Remove the carburetor.
  4.  
  5. Remove the intake and exhaust manifold assembly.
  6.  
  7. Drain the cooling system.
  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. Remove the water pump.
  2.  
  3. Remove the surge tank, water outlet and thermostat.
  4.  
  5. Remove the distributor and plug wires. Tag the wires for installation.
  6.  
  7. Remove the oil filter and bracket and position it out of the way.
  8.  
  9. Remove the coil.
  10.  
  11. Unbolt the oil filler tube from the head.
  12.  
  13. Remove and tag any wires connected to the head.
  14.  
  15. Remove the head bolts. There is a partially hidden head bolt next to the distributor adapter.
  16.  
  17. Lift off the head. Discard the head gasket.
  18.  

To install:
  1. Inspect the head for cracks, leaks or other damage. Replace leaky core plugs. Lay a straightedge across the head and check for flatness. Total deviation should not exceed 0.031 in. (0.7874mm). Localized deviation, between any two points, should not exceed 0.010 in. (0.254mm). Unevenness between the head and block, at any given point should not exceed 0.015 in. (0.381mm). If deviation is not within acceptable limits, the head should be replaced.
  2.  
  3. Thoroughly clean the mating surfaces of the head and block.
  4.  
  5. Check the head bolt holes for proper depth. To do this, place the head on the block, without the gasket. Insert the bolts into the holes, without the washers. Turn each bolt down, by hand. The bolts should be free enough to be turned all the way down by hand. The head of each bolt must tighten down on the head surface. If a bolt does not turn freely, clean and/or retap the hole as necessary. If a bolt will not turn all the way down, check for foreign matter in the hole. If there is no foreign matter, the hole will have to be deepened by retapping.
  6.  
  7. Obtain two bolts which are the thread size as the head bolts, but are at least 5 in. (127mm) longer. Cut the heads off the bolts and file screwdriver slots in each one. Install these bolts in positions 24 and 26, in the illustration.
  8.  
  9. Coat both sides of the new gasket with sealer. Position the gasket on the block. Make sure that the bolt holes line up.
  10.  
  11. Lower the head onto the block, using the guide bolts.
  12.  
  13. Coat the threads of the head bolts with sealer and install them. Turn the bolts down snugly, in the proper sequence. Remove the guide bolts and install bolts 24 and 26. Tighten all bolts, in the proper sequence, to 45 ft. lbs. (61 Nm).
  14.  
  15. Install any wires connected to the head.
  16.  
  17. Attach the oil filler tube to the head.
  18.  
  19. Install the coil.
  20.  
  21. Install the oil filter and bracket.
  22.  
  23. Install the distributor and plug wires.
  24.  
  25. Install the surge tank, water outlet and thermostat.
  26.  
  27. Install the water pump.
  28.  
  29. Install the intake and exhaust manifold assembly.
  30.  
  31. Install the carburetor.
  32.  
  33. Install the hood.
  34.  
  35. Fill the cooling system.
  36.  
  37. Start the engine and let it reach normal operating temperature. Shut off the engine and retighten the bolts to 45 ft. lbs. (61 Nm), in sequence. Recheck the bolt torque at 500 miles (800km) and 1,000 miles (1600km) after service.
  38.  

6-230 Engine

See Figure 28



Click image to see an enlarged view

Fig. Fig. 28: Make sure that the cylinder head bolts are tightened according to the sequence shown

This procedure requires a special tool.

  1. Remove the rocker arm cover.
  2.  
  3. Install camshaft sprocket remover W-268, or its equivalent, as shown. Tighten the nut to relieve tension on the camshaft.
  4.  
  5. Remove the capscrew, lock washer, flat washer and fuel pump eccentric from the camshaft sprocket.
  6.  
  7. Pull forward on the sprocket to remove it from the shaft. With the sprocket still engaged in the chain, release the tension on the tool by loosening the nut. Gently allow the sprocket to rest on the bosses in the cover.
  8.  

Do not rotate the crankshaft while the camshaft sprocket is removed in this manner. Do not attempt to remove the camshaft sprocket from the chain.

  1. Disconnect the lubrication tube from the head and block.
  2.  
  3. Remove the two timing chain cover-to-head bolts.
  4.  
  5. Remove the head bolts. Note that there are three short head bolts and eleven long ones. All bolts have flat washers.
  6.  
  7. Lift off the head and discard the gasket.
  8.  

To install:
  1. Inspect the head for cracks, leaks or other damage. Replace leaky core plugs. Lay a straightedge across the head and check for flatness. Total deviation should not exceed 0.003 in. (0.0762mm).
  2.  
  3. Thoroughly clean the mating surfaces of the head and block. Remove all carbon from the combustion chambers and tops of pistons. Clean all water and oil gallery holes.
  4.  
  5. Coat both sides of the new gasket with sealer. Position the gasket on the block. Make sure that the bolt holes line up.
  6.  
  7. Obtain two bolts which are the thread size as the head bolts, but are at least 5 1 / 2 in. (139.7mm). Cut the heads off the bolts and file screwdriver slots in each one.
  8.  
  9. Using a hoist, lower the head to within 1 / 4 in. (6mm) of the block.
  10.  
  11. Install the two modified bolts in bolt holes 12 and 14 in the head (see the torque sequence illustration) and screw them into the block to act as guide pins. This procedure is important, as these guide pins will prevent damage to the timing cover, chain and sprocket.
  12.  
  13. Lower the head into position and install the head bolts, with the exception of the No. 12 and No. 14 bolts, finger-tight. Leave the guide pins in holes 12 and 14.
  14.  
  15. Start the timing cover-to-head bolts into the head.
  16.  
  17. Tighten the 12 installed head bolts, in the sequence illustrated, to 35 ft. lbs. (48 Nm). Then, remove the guide pins and install the two head bolts in their places. Tighten them to 35 ft. lbs. (48 Nm) also.
  18.  

Late production engines have zinc plated bolts for these two locations. Make sure that these special bolts are used.

  1. Tighten all bolts, in the sequence shown, to 95 ft. lbs. (129 Nm).
  2.  
  3. Connect the lubrication tube from the head and block.
  4.  
  5. Install the camshaft sprocket and chain.
  6.  
  7. Install the capscrew, lock washer, flat washer and fuel pump eccentric on the camshaft sprocket.
  8.  
  9. Remove camshaft sprocket tool W-268.
  10.  
  11. Install the rocker arm cover.
  12.  

 
label.common.footer.alt.autozoneLogo