Jeep CJ/Scrambler 1971-1986 Repair Guide

Rocker Shafts and Rocker Studs

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See Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11

REMOVAL & INSTALLATION



4-134 Engine
  1. Remove the rocker arm cover attaching bolts and remove the rocker arm cover.
  2.  
  3. Remove the nuts from the rocker arm shaft support studs.
  4.  
  5. Remove the intake valve pushrods from the engine.
  6.  
  7. Install in the reverse order. Tighten the rocker arm retaining bolts to 30-33 ft. lbs.
  8.  



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Fig. Fig. 1: 4-134 valve train components

4-150 Engine
  1. Remove the rocker arm cover. The cover seal is RTV sealer. Break the seal with a clean putty knife or razor blade. Don't attempt to remove the cover until the seal is broken. To remove the cover, pry where indicated at the bolt holes.
  2.  
  3. Remove the two capscrews at each bridge and pivot assembly. It's best to remove the capscrews alternately, a little at a time each to avoid damage to the bridge.
  4.  
  5. Remove the bridges, pivots and rocker arms. Keep them in order.
  6.  
  7. Install the rocker arms and bridge and pivot assemblies. Tighten the capscrews to 19 ft. lbs.
  8.  
  9. Clean the mating surfaces of the cover and head.
  10.  
  11. Run a 1 / 8 in. (3mm) bead of RTV sealer around the mating surface of the head. Install the cover within 10 minutes! Don't allow any of the RTV material to drop into the engine! In the engine it will form and set and possibly block and oil passage. Torque the cover bolts to 36-60 inch lbs.
  12.  



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Fig. Fig. 2: 4-150 rocker arm assembly

4-151 Engine
  1. Remove the rocker arm cover.
  2.  
  3. Remove the rocker arm capscrew and ball.
  4.  
  5. Remove the rocker arm.
  6.  
  7. Install rocker arms. Tighten the capscrews to 20 ft. lbs. DO NOT OVERTORQUE!
  8.  
  9. Clean the mating surfaces of the cover and head.
  10.  
  11. Install the cover. Tighten the bolts to 36-60 inch lbs.
  12.  



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Fig. Fig. 3: 4-151 rocker arm and pushrod components

6-225 Engine
  1. Remove the crankcase ventilator valve from the right side valve cover.
  2.  
  3. Remove the four attaching bolts from the right and left side valve covers and remove both of the valve covers.
  4.  
  5. Unscrew, but do not remove, the bolts that attach the rocker arm assemblies to the cylinder heads.
  6.  
  7. Remove the rocker arm assemblies, with the bolts in place, from the cylinder heads.
  8.  
  9. Mark each of the pushrods so that they can be installed in their original positions.
  10.  
  11. Remove the pushrods.
  12.  

To install:
  1. Install the pushrods.
  2.  
  3. Install the rocker arm assemblies. Tighten the bolts to 30 ft. lbs., a little at a time.
  4.  
  5. Clean the mating surfaces of the covers and heads.
  6.  
  7. Install the valve covers using new gaskets. Torque the bolts to 36-60 in. lbs.
  8.  
  9. Install the crankcase ventilator valve from the right side valve cover.
  10.  
  11. Install the crankcase ventilator valve from the right side valve cover.
  12.  

1972-1974 6-232 and 6-258 Engines
  1. Remove the valve cover by removing the 6 valve cover attaching screws.
  2.  
  3. Loosen, but do not remove, the 6 bolts that attach the rocker arm assembly to the cylinder head.
  4.  
  5. Lift the whole rocker arm assembly off the head with the bolts in place.
  6.  
  7. Identify each of the pushrods so that they can be replaced in their original positions.
  8.  
  9. Remove the pushrods.
  10.  
  11. Install the rocker arm assembly. Tighten bolts, working evenly, from the center outward, to 22 ft. lbs.
  12.  
  13. Clean the mating surfaces of the valve cover and head.
  14.  
  15. Install the valve cover, using a new gasket. Torque the bolts to 36-60 ft. lbs.
  16.  



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Fig. Fig. 4: Rocker arm assembly as used on the 6-232, 6-258 and 8-304 engines

1973-78 6-232, 1975-86 6-258, and 1971 8-304 Engines

On these engines the rocker arms pivot on a bridged pivot that is secured with two capscrews. The bridged pivots maintain proper rocker arm-to-valve tip alignment.

  1. Remove the rocker cover and gasket.
  2.  
  3. Remove the two capscrews at each bridged pivot, backing off each capscrew one turn at a time to avoid breaking the bridge.
  4.  
  5. Remove each bridged pivot and corresponding pair of rocker arms and place them on a clean surface in the same order as they are removed.
  6.  

Bridged pivots, capscrews, rockers, and pushrods must all be reinstalled in their original positions.

  1. Clean all the parts in a suitable solvent and use compressed air to blow out the oil passages in the pushrods and the rocker arms. Replace any excessively worn parts.
  2.  
  3. Install rocker arms, pushrods and bridged pivots in the same positions from which they were removed.
  4.  

Be sure that the bottom end of each pushrod is centered in the plunger which they were removed. Be sure that the bottom end of each pushrod is centered in the plunger cap of each hydraulic valve tappet.

  1. Install the capscrews and tighten them one turn at a time, alternating between the two screws on each bridge. Tighten the capscrews to 21 ft. lbs. on the Sixes and 10 ft. lbs. on the 304 V8.
  2.  
  3. Install the rocker cover(s) with new gasket(s).
  4.  

1972 8-304 Engine

The 1972 8-304 has each rocker arm individually mounted on a separate stud. Each rocker assembly consists of the following: a rocker arm retaining stud, a rocker arm pivot ball, a rocker arm, and a retaining stud. Each assembly is removed and installed separately. To remove:

  1. Unscrew the rocker retaining nut from the stud and lift off the rocker arm and its pivot ball.
  2.  
  3. Remove the stud from the block with a wrench.
  4.  
  5. Label the pushrods so that they can be installed in their original positions and remove them from the block.
  6.  
  7. When installing the rocker arm retaining studs, use caution not to cross thread them. They are designed to cause an interference fit. Lubricate the studs with high pressure grease before installing them in the head. Install the rocker arm assemblies in the reverse order of removal. Tighten the rocker arm retaining nuts to 23 ft. lbs.
  8.  



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Fig. Fig. 5: Valve train components used on the 1972 V8 engine



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Fig. Fig. 6: Remove the valve cover retaining bolts



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Fig. Fig. 7: Remove the valve cover from the engine



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Fig. Fig. 8: Remove the rocker arm retaing bolts



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Fig. Fig. 9: Remove the rocker arm bridge assembly



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Fig. Fig. 10: Remove the rocker arm and pivot



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Fig. Fig. 11: The push rod can be remove from the engine at this time

 
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