GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 1578308  Size: SH
  1. Remove the intake camshaft position actuator. Refer to Camshaft Position Intake Actuator Replacement .
  2. Important: Remove each bolt on each cap one turn at a time until there is no spring tension pushing on the camshaft.

  3. Mark the bearing caps to ensure they are installed in the original position.
  4. Remove the bearing cap bolts.
  5. Remove the bearing caps.

  6. Object Number: 1578307  Size: SH
  7. Remove the intake camshaft (1).

  8. Object Number: 412183  Size: SH

    Important: Keep all of the roller followers and hydraulic adjusters in order so that they can be reinstalled in their respective locations.

  9. Remove the camshaft roller followers.

  10. Object Number: 412185  Size: SH
  11. Remove the hydraulic element lash adjusters.

Installation Procedure


    Object Number: 412185  Size: SH
  1. Install the hydraulic element lash adjusters into their bores in the cylinder head.
  2. Lubricate the hydraulic lash adjusters with GM PN 12345501 (Canadian PN 992704) or equivalent.

  3. Object Number: 412514  Size: SH
  4. Lubricate the valve tips with GM PN 12345501 (Canadian PN 992704) or equivalent.

  5. Object Number: 412183  Size: SH

    Important: Used roller followers MUST be returned to their original position on the camshaft. If the camshaft is being replaced, the roller followers actuated by the camshaft must also be replaced.

  6. Position the camshaft roller followers on the tip of the valve stem and on the lash adjuster. Lubricate the roller followers with GM PN 12345501 (Canadian PN 992704) or equivalent.

  7. Object Number: 1578307  Size: SH
  8. Install the intake camshaft (1). Lubricate with GM PN 12345501 (Canadian PN 992704) or equivalent.

  9. Object Number: 1578308  Size: SH
  10. Install the camshaft bearing caps. Hand tighten the cap bolts.
  11. Notice: Refer to Fastener Notice in the Preface section.

  12. Tighten the bearing cap bolts in increments of 3 turns until they are seated.
  13. Tighten
    Tighten the bolts to 10 N·m (89 lb in).

  14. Install the intake camshaft position actuator. Refer to Camshaft Position Intake Actuator Replacement .