Jeep Wagoneer/Commando/Cherokee 1957-1983 Repair Information

Cylinder Head

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REMOVAL & INSTALLATION



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 chapter.

4-134 Engine

  1. Drain the coolant.
  2.  


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

  1. Remove the upper radiator hose.
  2.  
  3. Remove the carburetor.
  4.  
  5. On early engines, remove the bypass 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. Remove the pushrods and the valve lifters if further disassembly is to be carried out.
  16.  
  17. Reverse the above procedure to install the cylinder head. Tighten the head bolts first to 40 ft. lb., then to the specified torque in the correct sequence.
  18.  

6-225 Engine

  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.  


CAUTION
The EPA warns that prolonged contact with used engine oil may cause a number of skin disorders, including cancer! You should make every effort to minimize you exposure to used engine oil. Protective gloves should be worn when changing the oil. Wash your hands and any other exposed skin areas as soon as possible after exposure to used engine oil. Soap and water, or waterless hand cleaner should be used.

  1. Remove the valve cover and the rocker assemblies. Mark these parts so that they can be reinstalled in exactly the same positions.
  2.  
  3. 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.
  4.  
  5. Installation is the reverse of removal. Make sure that the cylinder head(s) and block mating surfaces are clean. Always use new gaskets. Torque the head bolts in the sequence shown, in three progressive passes, to the torque given in the Torque specifications chart.
  6.  

6-226 Engine See Figure 1

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Fig. Fig. 1: Cylinder head bolt tightening sequence 6 cyl-226 engine

  1. Remove the engine cover and tunnel.
  2.  
  3. Remove the carburetor.
  4.  
  5. Remove the intake and exhaust manifold assembly.
  6.  
  7. Drain the cooling system.
  8.  


CAUTION
When draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is 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.  
  19. 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. Localized deviation, between any two points, should not exceed 0.010 in. Uneveness between the head and block, at any given point should not exceed 0.015 in. If deviation is not within acceptable limits, the head should be replaced.
  20.  

  1. Thoroughly clean the mating surfaces of the head and block.
  2.  
  3. 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.
  4.  
  5. Obtain two bolts which are the thread size as the head bolts, but are at least 5 inches 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.
  6.  
  7. Coat both sides of the new gasket with sealer. Position the gasket on the block. Make sure that the bolt holes line up.
  8.  
  9. Lower the head onto the block, using the guide bolts.
  10.  
  11. 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. Torque all bolts, in the proper sequence, to 45 ft. lb.
  12.  
  13. Install all other parts in the reverse order of removal. Fill the cooling system.
  14.  
  15. Start the engine and let it reach normal operating temperature. Shut off the engine and retorque the bolts to 45 ft. lbs., in sequence. Recheck the bolt torque at 500 miles and 1,000 miles after service.
  16.  

6-230 Engine See Figure 2

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Fig. Fig. 2: Cylinder head bolt tightening sequence 6 cyl-230 engine

This procedure requires a special tool.

  1. Remove the camshaft 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, lockwasher, 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.  


CAUTION
The EPA warns that prolonged contact with used engine oil may cause a number of skin disorders, including cancer! You should make every effort to minimize you exposure to used engine oil. Protective gloves should be worn when changing the oil. Wash your hands and any other exposed skin areas as soon as possible after exposure to used engine oil. Soap and water, or waterless hand cleaner should be used.

  1. Lift off the head and discard the gasket.
  2.  
  3. 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 .003 in.
  4.  
  5. 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.
  6.  
  7. Coat both sides of the new gasket with sealer. Position the gasket on the block. Make sure that the bolt holes line up.
  8.  
  9. Obtain two bolts which are the thread size as the head bolts, but are at least 5 1 / 2 inches long. Cut the heads off the bolts and file screwdriver slots in each one.
  10.  
  11. Using a hoist, lower the head to within 1 / 4 inch of the block.
  12.  
  13. 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.
  14.  
  15. Lower the head into position and install the head bolts, with the exception of the #12 and 14 bolts, finger-tight. Leave the guide pins in holes 12 and 14.
  16.  
  17. Start the timing cover-to-head bolts into the head.
  18.  
  19. Torque the 12 installed head bolts, in the sequence illustrated, to 35 ft. lb. Then, remove the guide pins and install the two head bolts in their places. Torque them to 35 ft. lb. also.
  20.  

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

  1. Torque all bolts, in the sequence shown, to 95 ft. lb.
  2.  
  3. Install all other parts in reverse order of removal.
  4.  

6-232 and 258 Engines See Figure 3

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Fig. Fig. 3: Cylinder head bolt tightening sequence 6 cyl-232 and 258 engines

  1. Drain the cooling system and disconnect the hoses at the thermostat housing.
  2.  


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

  1. Remove the cylinder head cover (valve cover), the gasket, the rocker arm assembly, and the pushrods.
  2.  

The pushrods must be replaced in their original positions.

  1. Remove the intake and exhaust manifold from the cylinder head.
  2.  
  3. Disconnect the spark plug wires and the spark plugs to avoid damaging them.
  4.  
  5. Disconnect the temperature sending unit wire, ignition coil and bracket assembly from the engine.
  6.  
  7. Remove the cylinder head bolts, the cylinder head and gasket from the block.
  8.  
  9. To install, reverse the above procedure. Tighten the headbolts to the specified torque, using the proper sequence. Coat the threads of bolt #11, in the illustration with waterproof sealer. Torque this bolt to 75 ft. lb. Torque all other bolts to 85 ft. lb.
  10.  

Some head bolts used on the spark plug side of the 1984 6-258 were improperly hardened and may break under the head during service or at head installation while torquing the bolts. Engines with the defective bolts are serial numbers 310C06 through 310C14. Whenever a broken bolt is found, replace all seven bolts on the spark plug side of the head with bolt #400 6593. Torque all bolts to 85 ft. lb., except #11 in the torque sequence, which should be coated with sealer and torqued to 75 ft. lb.

8-304, 8-360 and 8-401 Engines See Figures 4 through 11

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Fig. Fig. 4: Cylinder head bolt tightening sequence 8 cyl-304, 360 and 401 engines



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Fig. Fig. 5: Loosen the valve cover retaining bolts



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Fig. Fig. 6: Remove the valve cover



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Fig. Fig. 7: Remove the rocker arm assemblies ...



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Fig. Fig. 8: ... then remove the pushrods



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Fig. Fig. 9: Use a breaker bar to loosen the cylinder head bolts



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Fig. Fig. 10: Before removing the cylinder head from the engine block cover the intake manifold opening with a rag or paper towels to avoid contamination



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Fig. Fig. 11: Use a gasket scraper to clean the old gasket from the cylinder head

  1. Drain the cooling system.
  2.  


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

  1. When removing the right cylinder head, remove the heater core housing from the firewall.
  2.  
  3. Remove the valve cover(s) and gasket(s).
  4.  
  5. Remove the rocker arm assemblies and the pushrods.
  6.  

The pushrods must be replaced in their original positions.

  1. Remove the spark plugs to avoid damaging them.
  2.  
  3. Remove the intake manifold with the carburetor still attached.
  4.  
  5. Remove the exhaust pipes at the flange of the exhaust manifold. When replacing the exhaust pipes, it is advisable to install new gaskets at the flange.
  6.  
  7. Loosen all of the drive belts.
  8.  
  9. Disconnect the battery ground cable from the right cylinder head.
  10.  
  11. Disconnect the air pump bracket from the left cylinder head.
  12.  
  13. Remove the cylinder head bolts and lift the head(s) from the cylinder block.
  14.  
  15. Remove the cylinder head gasket from the head or the block.
  16.  
  17. To install, reverse the above procedure. Torque the bolts in the sequence shown.
  18.  

The second head bolt from the front, on the bottom row, must have its threads coated with sealer when installed in order to prevent coolant leakage. First, tighten all bolts to 80 ft. lb., then tighten to the specified torque. Follow the correct sequence.

8-327 and 350 Engines See Figures 12 through 16

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Fig. Fig. 12: Cylinder head bolt tightening sequence 8 cyl-350 engine



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Fig. Fig. 13: Cylinder head bolt tightening sequence 6 cyl-327 engine



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Fig. Fig. 14: When removing nuts, bolts and other parts, place them in a tray or other container



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Fig. Fig. 15: Use a gasket scraper to remove the bulk of the old head gasket from the mating surface



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Fig. Fig. 16: An electric drill equipped with a wire wheel will expedite complete gasket removal

  1. Drain the cooling system at the radiator and at the engine block.
  2.  


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

  1. Disconnect the battery cables from the battery and remove the alternator and alternator bracket assembly from the engine.
  2.  
  3. Remove the air cleaner assembly.
  4.  
  5. Remove the rocker covers and gaskets and remove the rocker assemblies, together with the pushrods.
  6.  

The pushrods must be reinstalled in the same positions from which they were removed. Identify each pushrod so that this can be accomplished.

  1. Disconnect the exhaust pipes from the exhaust manifolds by removing the nuts from the attaching bolts of the clamp. Remove the donut gasket.
  2.  
  3. Remove the distributor.
  4.  
  5. Remove the cap screws, lockwashers, nuts, and flat washers that secure the intake manifold to the cylinder heads.
  6.  
  7. Remove the intake manifold with the carburetor attached from the engine. Remove the gaskets and discard them.
  8.  
  9. Remove the bolts holding the cylinder head to the block. Removing one head bolt on the left bank frees the oil dipstick and tube which may now be lifted off. There is a rubber bushing on the lower end of the tube; take care not to lose the rubber bushing.
  10.  
  11. Lift the heads off the block and remove and discard the cylinder head gaskets. Remove all traces of gasket material from all mating surfaces on both the heads and the intake manifold.
  12.  
  13. Install the cylinder heads and assemble the engine in the reverse order of removal and disassembly. Torque the head bolts and intake manifold bolts in the correct sequence and to the proper specifications.
  14.  

 
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