GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • EN 46105 Camshaft Locking Tools
    • EN-48313 Timing Chain Retention Tool
    • EN 46111 Crankshaft Rotation Socket

Removal Procedure

  1. Remove the engine covers. Refer to Engine Cover Replacement .
  2. Remove the upper intake manifold with the lower intake manifold. Refer to Lower Intake Manifold Replacement .
  3. Remove the right side camshaft cover. Refer to Camshaft Cover Replacement - Right Side .
  4. Remove the camshaft position sensors. Refer to Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust and Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake .
  5. Remove the camshaft position (CMP) actuator solenoids. Refer to (if fitted) Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Exhaust and Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake .
  6. Remove the crankshaft balancer. Refer to Crankshaft Balancer Removal .

  7. Object Number: 1961751  Size: SH
  8. Rotate the crankshaft with the EN 46111 until the camshafts are in a neutral (low tension) position. The camshaft flats will be parallel with the camshaft cover rail (1).

  9. Object Number: 1958037  Size: SH
  10. Install the EN 46105  (2) onto the rear of the right side camshafts (1)
  11. Notice: Refer to Torque Reaction Against Timing Drive Chain Notice in the Preface section.


    Object Number: 1961778  Size: SH

    Important: 

       • Use an open-end wrench at the camshaft hex to prevent camshaft/engine rotation.
       • DO NOT remove the camshaft position actuator to camshaft retaining bolt at this time.

  12. Loosen the right side intake camshaft position actuator to camshaft retaining bolt.
  13. Loosen the EN-48313 so that the legs are retracted.

  14. Object Number: 1961773  Size: SH

    Important: The front engine cover is removed in the following graphics for illustration purposes and is not required to perform the procedure.

  15. Insert the EN-48313 between the camshaft actuators, rearward of the timing chain until the top line that is scribed in the body of the tool (1) is adjacent to the top surface of the cylinder head (2). This is the approximate installed position.

  16. Object Number: 1961772  Size: SH
  17. Make sure that the feet (2) on the legs (1) of the EN-48313 are facing the front of the engine.
  18. Important: DO NOT tighten EN-48313 at this stage.

  19. Partially expand the legs (1) of the EN-48313 by turning the T-shaped handle clockwise.
  20. Important: Make sure that the feet (2) of the EN-48313 is correctly engaged into one of the link pockets to prevent chain slipping during tightening.

  21. Continue expanding the EN-48313 until the feet (2) contact the timing chain.
  22. Notice: Refer to Torque Reaction Against Timing Drive Chain Notice in the Preface section.

  23. Hand tighten the EN-48313 .
  24. Important: DO NOT allow the body of the tool to rotate when tightening the T-handle.

  25. Use an open-end wench on the hex cast into the body of the EN-48313 and hand tighten the T-handle.
  26. Use an open-end wrench on the hex cast into the right intake and exhaust camshafts and rotate the camshafts towards each other in order create slack in the chain between the actuators.
  27. The EN-48313 is now correctly installed to hold the timing chain in position.
  28. Important: Make sure that the camshaft timing chain and the camshaft position actuators are marked for correct assembly.

  29. Mark the timing chain and the camshaft position actuators.

  30. Object Number: 1961775  Size: SH
  31. Remove the right side intake camshaft position actuator to camshaft retaining bolt (1).
  32. Remove the right side intake camshaft position actuator (2).

Installation Procedure


    Object Number: 1958041  Size: SH
  1. Make sure the correct camshaft position actuator is installed. Observe the body of the camshaft position actuator for the "IN" marking (2). The marking is for an intake camshaft position actuator.
  2. Make sure the correct timing mark is used. Observe the outer ring of the camshaft position actuator for the "R" and triangle marking (1). The marking is for alignment to the highlighted timing chain link on the right side of the engine.

  3. Object Number: 1961775  Size: SH
  4. Install the right side intake camshaft position actuator (2).
  5. Important: 

       • Make sure that the marks on the camshaft position actuators and the timing chain are aligned.
       • DO NOT tighten the right intake camshaft position actuator to camshaft retaining bolt (1) at this time.

  6. Install the right side intake camshaft position actuator to camshaft retaining bolt (1).
  7. DO NOT fully tighten at this stage.

  8. Remove the EN 46108 EN 48313.
  9. Notice: Refer to Torque Reaction Against Timing Drive Chain Notice in the Preface section.

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1961778  Size: SH

    Important: Use an open-end wrench at the camshaft hex to prevent camshaft/engine rotation.

  10. Tighten the camshaft position actuator to camshaft retaining bolt.
  11. Tighten
    Tighten the bolt to 58 N·m (43 lb ft).


    Object Number: 1958037  Size: SH
  12. Remove the EN 46105  (2) from the rear of the right side camshafts (1)
  13. Install the camshaft position (CMP) actuator solenoids. Refer to (if fitted) Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Exhaust and Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake .
  14. Install the camshaft position sensors. Refer to Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust and Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake .
  15. Install the crankshaft balancer. Refer to Crankshaft Balancer Installation .
  16. Install the right side camshaft cover. Refer to Camshaft Cover Replacement - Right Side .
  17. Install the upper intake manifold with the lower intake manifold. Refer to Lower Intake Manifold Replacement .
  18. Install the engine covers. Refer to Engine Cover Replacement .