GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • EN 46328 Camshaft Holding Tool
    • J 39946 Crankshaft Socket

Removal Procedure


    Object Number: 517185  Size: SH
  1. Remove the oil pump. Refer to Oil Pump Replacement.
  2. Using the J 39946 , rotate the crankshaft until the primary timing gear marks (1) are adjacent to each other as shown.
  3. Remove the right camshaft position actuator housing. DO NOT remove the actuator solenoids from the housing. Refer to Camshaft Position Actuator Housing Replacement - Right Side.
  4. Warning: Refer to Camshaft Holding Tool Warning in the Preface section.


    Object Number: 1275659  Size: SH
  5. Install the EN 46328  (1) on the bank 1 (right) camshafts (2).

  6. Object Number: 1276761  Size: SH
  7. Loosen and remove the right secondary timing chain tensioner bolts and tensioner. Refer to Secondary Camshaft Drive Chain Tensioner Replacement - Right Side.
  8. Caution: Refer to Torque Reaction Against Timing Drive Chain Caution in the Preface section.


    Object Number: 1275678  Size: SH
  9. Use an open-end wrench on the hex cast into the camshaft in order to prevent the camshaft from rotating when removing the camshaft oil control valve.
  10. Loosen and remove the bank 1 (right) exhaust camshaft position oil control valve.
  11. Slide the right exhaust camshaft position actuator off of the camshaft and remove the secondary timing chain from the camshaft actuator teeth.
  12. Caution: Refer to Torque Reaction Against Timing Drive Chain Caution in the Preface section.


    Object Number: 1275677  Size: SH
  13. Use an open-end wrench on the hex cast into the camshaft in order to prevent the camshaft from rotating when removing the camshaft oil control valve.
  14. Loosen and remove the bank 1 (right) intake camshaft position oil control valve.
  15. Slide the right intake camshaft position actuator off of the camshaft and remove the secondary timing chain from the camshaft actuator teeth.
  16. Remove the right secondary timing chain from the engine.
  17. Clean and inspect the camshaft timing drive components. Refer to Camshaft Timing Drive Components Cleaning and Inspection.

Installation Procedure


    Object Number: 1276767  Size: SH
  1. The secondary timing chain has 3 black links that aid in timing the camshaft position actuators to the intermediate sprocket.
  2. The black link (2) is aligned with the bank 1 exhaust actuator timing mark. The black link (3) is aligned with the bank 1 intake actuator timing mark.
  3. The black link (1) is aligned with the intermediate sprocket.

  4. Object Number: 1272585  Size: SH
  5. The intermediate sprocket right bank timing mark is labeled right bank (RB) as shown.
  6. Assemble the secondary timing chain to the intermediate sprocket aligning the sprocket RB timing mark to the timing chain black link.
  7. Caution: Refer to Torque Reaction Against Timing Drive Chain Caution in the Preface section.


    Object Number: 1276769  Size: SH
  8. Align the timing mark (5) of the RB intake camshaft position actuator with the timing chain black link (8) and install the actuator on the camshaft with the actuator timing mark perpendicular (90 degrees) to the cylinder head deck surface near the top of its rotation.
  9. Loosely install the oil control valve (2) to secure the intake actuator.
  10. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 1275677  Size: SH
  11. Use an open-end wrench on the hex cast into the camshaft in order to prevent the camshaft from rotating when tightening the oil control valve to 120 N·m (89 lb ft).
  12. Caution: Refer to Torque Reaction Against Timing Drive Chain Caution in the Preface section.


    Object Number: 1276769  Size: SH
  13. Align the timing mark (3) of the RB exhaust camshaft position actuator with the timing chain black link and install the actuator on the camshaft with the actuator timing mark perpendicular (90 degrees) to the cylinder head deck surface near the top of its rotation.
  14. Loosely install the oil control valve (1) to secure the exhaust actuator.

  15. Object Number: 1275677  Size: SH
  16. Use an open-end wrench on the hex cast into the camshaft in order to prevent the camshaft from rotating when tightening the oil control valve to 120 N·m (89 lb ft).

  17. Object Number: 1276761  Size: SH
  18. Install the right secondary timing chain tensioner. Refer to Secondary Camshaft Drive Chain Tensioner Replacement - Right Side.
  19. Remove the EN 46328 .
  20. Install the right camshaft position actuator housing. Refer to Camshaft Position Actuator Housing Replacement - Right Side.
  21. Install the oil pump. Refer to Oil Pump Replacement.