GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 39946 Crankshaft Socket
    • EN 46328 Camshaft Holding Tool

Removal Procedure


    Object Number: 1272598  Size: SH
  1. Remove the right secondary camshaft tensioner (2). Refer to Secondary Camshaft Drive Chain Tensioner Replacement - Right Side .
  2. Remove the right camshaft position actuator housing. DO NOT remove the camshaft sensors from the housing. Refer to Camshaft Position Actuator Housing Replacement - Right Side .

  3. Object Number: 1275681  Size: SH
  4. Using the J 39946 (1) , rotate the crankshaft until both camshaft position actuator timing marks are at the top of their rotation.
  5. Caution: Refer to Camshaft Holding Tool Caution in the Preface section.


    Object Number: 1275659  Size: SH
  6. Install the EN 46328 (2) .

  7. Object Number: 1275692  Size: SH

    Important: The secondary timing chain has black links that are used for alignment when the primary and secondary timing gear and chain assemblies are being installed together. IT IS NOT NECESSARY for the black chain links to be aligned with the camshaft actuator timing marks when the secondary chain and gear components are being serviced separately.

  8. Use a paint stick to create a mark on the timing chain link (1) adjacent to each camshaft position actuator timing mark (3).
  9. Use a paint stick to create a mark on a primary chain link and intermediate primary chain sprocket tooth adjacent to the primary chain link.

  10. Object Number: 1275677  Size: SH
  11. Use an open end wrench on the hex cast into the right intake camshaft to prevent the camshaft from rotating when loosening the camshaft oil control valve.

  12. Object Number: 1261666  Size: SH
  13. Loosen and remove the right intake oil control valve.
  14. Slide the right intake camshaft actuator off of the camshaft, disengage the sprocket teeth from the secondary timing chain, and remove the actuator.

  15. Object Number: 685331  Size: SH
  16. Remove the upper right secondary camshaft drive chain guide bolt.

  17. Object Number: 685347  Size: SH
  18. Remove the lower right secondary camshaft drive chain guide bolt.

  19. Object Number: 685348  Size: SH
  20. Remove the right secondary camshaft drive chain guide.
  21. Clean and inspect the camshaft timing drive components. Refer to Camshaft Timing Drive Components Cleaning and Inspection .

Installation Procedure


    Object Number: 685348  Size: SH
  1. Position the right secondary camshaft drive chain guide in through the right front cylinder head as shown.
  2. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 685347  Size: SH
  3. Install the right secondary camshaft drive chain guide bolts.
  4. Tighten
    Tighten the secondary camshaft drive chain guide bolts to 25 N·m (18 lb ft).

  5. Install the right secondary camshaft drive chain tensioner. Refer to Secondary Camshaft Drive Chain Tensioner Replacement - Right Side .
  6. Install the right intake camshaft actuator. Refer to Camshaft Position Actuator Replacement - Bank 1 (Right Side) Intake .

  7. Object Number: 1275693  Size: SH
  8. Ensure that the previously created paint marks (1, 3) still line up with the sprocket timing marks (2, 4).