GM S-Series Pick-ups and SUV's 1994-1999 Repair Guide

Rocker Arms and Pushrods

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REMOVAL & INSTALLATION



2.2L Engine

See Figures 1 through 5

  1. Remove the rocker arm cover from the cylinder head.
  2.  
  3. Unfasten the rocker arm retaining nut, then remove the arm and ball. If necessary, withdraw the pushrod form the cylinder head.
  4.  

Valve train components which are to be reused MUST be installed in their original positions. If removed, be sure to tag or arrange all rocker arms and pushrods to assure proper installation.



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Fig. Fig. 1: Unfasten the rocker arm retaining nut. A long extension may be needed to avoid hitting your hand on any of the surrounding components



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Fig. Fig. 2: Once the nut is loosened, remove it from the rocker arm stud



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Fig. Fig. 3: Remove the rocker ball and washer (which should be inside the rocker arm). Be careful not to loose the ball



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Fig. Fig. 4: If necessary, remove the pushrod



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Fig. Fig. 5: Use a torque wrench to tighten the rocker arm nuts to specification

To install:
  1. Inspect the rocker arms, balls and pushrods for damage or wear and replace, as necessary:
    1. Check the rocker arms, balls and their mating surfaces. Make sure the surfaces are smooth and free from scoring or other damage.
    2.  
    3. Check the rocker arm areas that contact the valve stems and the sockets that contact the pushrods, make sure these areas are smooth and free of both damage and wear.
    4.  
    5. Make sure the pushrods are not bent; this can be determined by rolling them on a flat surface. Check the ends of the pushrods for scoring or roughness
    6.  
    7. Inspect the rocker arm bolts for thread damage. Check the rocker arm bolts in the shoulder area for contact damage with the rocker arm.
    8.  

  2.  
  3. If removed, install the pushrods making sure they are seated within the lifters.
  4.  
  5. If installing new rocker arms and balls, coat the friction surfaces using Dri-Slide Molykote® or an equivalent pre-lube.
  6.  

When tightening the rocker arm retainers, make sure the lifter for that valve is resting on the base circle of the camshaft NOT on the lobe. DO NOT overtighten the retainers.

  1. Install the rocker arms and ball, then tighten the retaining nuts to 22 ft. lbs. (30 Nm) on 1994-97 models and 19 ft. lbs. (25 Nm) on 1998-99 models.
  2.  

Valve lash is NOT adjustable on the 2.2L gasoline engine.

  1. Install the rocker arm cover, then start and run the engine to check for leaks.
  2.  

4.3L Engine

See Figures 6 through 10



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Fig. Fig. 6: Unfasten the rocker arm nut



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Fig. Fig. 7: Remove the ball washer ... .



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Fig. Fig. 8: ... . then remove the rocker arm



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Fig. Fig. 9: Remove the pushrod from the cylinder head



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Fig. Fig. 10: A piece of cardboard may be used to hold the pushrods in order

  1. Remove the rocker arm cover(s) from the cylinder head.
  2.  
  3. Remove the rocker arm nut, the rocker arm and the ball washer.
  4.  

If only the pushrod is to be removed, loosen the rocker arm nut, swing the rocker arm to the side and remove the pushrod.

  1. Valve train components which are to be reused MUST be installed in their original positions. If removed, be sure to tag or arrange all rocker arms and pushrods to assure proper installation.
  2.  
  3. Withdraw the pushrod from the cylinder head.
  4.  

To install:
  1. Inspect and replace components if worn or damaged.
  2.  
  3. Coat the bearing surfaces of the rocker arms and the rocker arm ball washers with Molykote® or equivalent pre-lube.
  4.  
  5. Install the pushrods making sure that they seat properly in the lifter.
  6.  
  7. Install the rocker arms, ball washers and the nuts.
  8.  
  9. For the 4.3L engines which are equipped with screw-in type rocker arm studs with positive stop shoulders, tighten the rocker arm adjusting nuts against the stop shoulders to 20 ft. lbs. (27 Nm) on 1994-96 models and 18 ft. lbs. (25 Nm) on 1997-99 models. No further adjustment is necessary, or possible.
  10.  
  11. For most 4.3L engines which are not equipped with screw-in type rocker arm studs and positive stop shoulders, properly adjust the valve lash. For details on valve lash adjustment, please refer to the procedure in Routine Maintenance .
  12.  
  13. Install the rocker arm cover(s) to the cylinder head.
  14.  
  15. Start and run the engine, then check for leaks and for proper ignition timing adjustment.
  16.  

 
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