GM Service Manual Online
For 1990-2009 cars only

    Object Number: 195336  Size: SH
  1. Turn the valve rocker arm nuts clockwise until all of the valve lash is removed.
  2. Turn the crankshaft clockwise until the alignment mark on the crankshaft balancer is aligned with the notch in the engine front cover tab.
  3. Look at the number 1 cylinder valves as the crankshaft balancer alignment mark approaches the notch in the engine front cover tab. If a valve moves as the alignment mark moves into position, the engine is in the number 6 firing position. If this happens, turn the crankshaft clockwise one revolution in order to reach the number 1 cylinder firing position.

  4. Object Number: 22759  Size: SH
  5. With the engine in the number 1 firing position, adjust the exhaust valves for cylinders number 1, 3, 4, and 8 and the intake valves for cylinders number 1, 2, 5, and 7.
  6. 4.1. Turn the valve rocker arm nut counter clockwise until the valve lash is felt in the valve pushrod.
    4.2. Turn the valve rocker arm nut clockwise until all the valve lash is removed (zero valve lash).

    Zero valve lash can be felt by moving the valve pushrod up and down between your thumb and forefinger until there is no more up and down movement of the valve push rod.

    4.3. When all the valve lash is removed, then turn the valve rocker arm nut clockwise 1 additional turn (360 degrees).

    Object Number: 195336  Size: SH
  7. Turn the crankshaft clockwise 1 revolution until the alignment mark on the crankshaft balancer is aligned with the notch in the engine front cover tab.

  8. Object Number: 22759  Size: SH
  9. With the engine in the number 6 firing position, adjust the exhaust valves for cylinders number 2, 5, 6, and 7 and the intake valves for cylinders number 3, 4, 6, and 8.
  10. 6.1. Turn the valve rocker arm nut counter clockwise until the valve lash is felt in the valve pushrod.
    6.2. Turn the valve rocker arm nut clockwise until all the valve lash is removed (zero valve lash).

    Zero valve lash can be felt by moving the valve pushrod up and down between your thumb and forefinger until there is no more up and down movement of the valve push rod.

    6.3. When all the valve lash is removed, then turn the valve rocker arm nut clockwise 1 additional turn (360 degrees).