For 1990-2009 cars

### Removal Procedure

Important: Place the valve rocker arms, the valve rocker arm balls, and the pushrods in a rack in order to ensure reinstallation to the original locations.

1. Remove the valve rocker arm covers. Refer to Valve Rocker Arm Cover Replacement .
2. Remove the valve rocker arm nuts (1) and the valve rocker arm balls (2).
3. Remove the valve rocker arms (3) and studs (4).
4. Remove the valve rocker arm pushrods.

### Installation Procedure

Important: Coat the bearing surfaces of the valve rocker arms and the valve rocker arm balls with pre lube, GM P/N 1052365 or the equivalent prior to installation. Install these components and the pushrods in the original locations, prior to removal.

1. Install the valve rocker arm pushrods.

Ensure that the pushrods seat in the lifter sockets.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Important: Coat the threads of the valve rocker arm studs with sealant GM P/N 12346004 or equivalent prior to installation.

2. Install the valve rocker arm studs (4).

Tighten
Tighten the valve rocker arm studs to 68 N·m (50 lb ft).

3. Install the valve rocker arms (3).
4. Install the valve rocker arm balls (2) and the valve rocker arm nuts (1).

Tighten
Tighten the valve rocker arm nuts until the lash is eliminated.

5. Turn the crankshaft until the cast arrow on the crankshaft balancer hub is in the 12 o'clock position and the number 1 cylinder is in the firing position (top dead center).
6. Watch the number 1 cylinder valves as the crankshaft balancer hub arrow approaches the 12 o'clock position. If a valve moves as the arrow moves to the position, the engine is in the number 6 cylinder firing position. Turn the crankshaft one more revolution to reach the number 1 cylinder firing position.
7. With the engine in the number 1 cylinder firing position, adjust the following valves:

• | Exhaust 1, 3, 4, 8

• | Intake 1, 2, 5, 7

8. Back off the valve rocker arm nut until the lash is felt in the pushrod.
9. Tighten the valve rocker arm nut until all of the lash is removed.
10. Zero lash can be felt by moving the pushrod up and down using the thumb and the forefinger until there is no more movement.
11. When all the free play has been removed, tighten the valve rocker arm nut one additional turn.
12. Turn the crankshaft one revolution until the hub arrow is again at 12 o'clock position. This is the number 6 cylinder firing position. Adjust the following valves:

• | Exhaust 2, 5, 6, 7

• | Intake 3, 4, 6, 8

13. Install the valve rocker arm covers. Refer to Valve Rocker Arm Cover Replacement .