GM Firebird 1982-1992 Repair Guide

Rocker Arms

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REMOVAL & INSTALLATION



See Figures 1, 2, 3 and 4



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Fig. Fig. 1: Common rocker arm components



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Fig. Fig. 2: 2.5L rocker arm components



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Fig. Fig. 3: Remove the rocker arm retaining nut



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Fig. Fig. 4: Then remove the rocker arm pivot

Be sure to keep all the components in the exact order of removal so they may be installed in there original location; adjust the valve lash after replacing the rocker arms. Coat the replacement rocker arm and ball with engine oil before installation.

Rocker arms studs that have damaged threads or are loose in the cylinder heads may be replaced by reaming the bore and installing oversize studs. Oversizes available are 0.003 in. (0.076mm) and 0.013 in (0.33mm). The bore may also be tapped and screw-in studs installed. Several aftermarket companies produce complete rocker arm stud kits with installation tools.

The 2.5L engine use bolts instead of studs, 2.8L and 3.1L engines use threaded studs, the 3.4L, 5.0L and 5.7L engines use press fit studs.

Except 3.8L Turbo and 2.5L Engines
  1. Disconnect the negative (-) battery cable.
  2.  
  3. Remove the rocker arm cover as outlined in this section
  4.  
  5. Remove the rocker arm nuts, balls and rocker arms. Place components in a rack so they can be reinstalled in the same location.
  6.  

To install:
  1. Coat the bearings surfaces with a thin coating of Molykote® or its equivalent.
  2.  
  3. Install the pushrods and make sure the rod is in the lifter seat.
  4.  
  5. Install the rocker arm, balls and nut. Tighten the nut until all lash is eliminated.
  6.  
  7. The engine must be on the No. 1 firing position before proceeding. This may be determined by placing your fingers on the No. 1 rocker arms as the mark crankshaft damper is rotated towards the "0'' on the timing tab. If the arms did not move, it is in the No. 1 firing position. If they did move, turn the crankshaft one full revolution to reach the No. 1 position. Remember, the mark on the crankshaft balancer must be aligned with the "0'' on the timing tab.
  8.  
  9. Adjust the valves as follows:
  10.  

V6 ENGINES

With the engine on the number 1 firing position, exhaust valves 1, 2 and 3 and intake valves 1, 5 and 6 may be adjusted. Back out the adjusting nut until lash is felt at the pushrod. Tighten the adjusting nut until all lash is removed, then tighten the nut an additional 1 1 / 2 turns to center the lifter plunger. Turn the engine one revolution until the "0'' timing mark is once again aligned. Exhaust valves 4, 5 and 6 and intake valves 2, 3 and 4 may be adjusted.

V8 ENGINES

With the engine on the number 1 firing position, exhaust valves 1, 3, 4 and 8, intake valves 1, 2, 5 and 7 may be adjusted. Back out the adjusting nut until lash is felt at the pushrod. Tighten the adjusting nut until all lash is removed, then tighten an additional 1 turn to center the lifter plunger. Turn the engine one revolution until the 0 timing mark is once again aligned. Exhaust valves 2, 5, 6 and 7, intake valves 3, 4, 6 and 8 may be adjusted.

  1. Install the rocker arm cover.
  2.  

2.5L Engine

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the valve cover.
  4.  
  5. Remove the rocker arm bolt, ball and rocker arm.
  6.  
  7. Remove the pushrods, if necessary. Place components in a rack so they can be reinstalled in the same location.
  8.  

To install:
  1. Coat the bearings surfaces with a thin coating of Molykote® or its equivalent.
  2.  
  3. Install the pushrod, if removed, through the cylinder head and into the lifter seat.
  4.  
  5. Install the rocker arm, ball and bolt. Torque to 22 ft lbs. (30 Nm).
  6.  
  7. Install the valve cover.
  8.  

3.8L Turbo Engine

  1. Disconnect the negative battery cable.
  2.  
  3. Remove valve covers.
  4.  

Mark or place components in order so they can be installed in the same location from which they were removed.

  1. Remove rocker arm pedestal bolts and double ended bolts. Note the position of the double ended bolts for reassembly.
  2.  
  3. Remove the rocker arm pedestals, rocker arms and pedestal retainers.
  4.  
  5. Remove the pushrods.
  6.  

To install:
  1. Install the pushrods. Be sure they seat in the lifters.
  2.  
  3. Install the pedestal retainers, rocker arms and rocker arm pedestals.
  4.  
  5. Install the rocker arm pedestal bolts. Tighten them to 44 ft lbs. (60 Nm).
  6.  
  7. Install the valve covers. Be sure to use new valve cover gaskets.
  8.  

 
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