GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 44221 Camshaft Holding Tool
    • J 45059 Angle Meter

    Object Number: 748323  Size: SH
  1. Install J 44221 with the camshaft flats up and the number 1 cylinder at top dead center. The crankshaft pin should be at 12 o'clock when the number 1 piston is at top ded center.

  2. Object Number: 637578  Size: SH
  3. Compress the tensioner and lock in place.
  4. Install the crankshaft sprocket.
  5. Install the intake camshaft sprocket into the timing chain.
  6. Align the (dark) link of the timing chain with the timing mark on the intake camshaft sprocket (1).
  7. Feed the timing chain down through the opening in the head.
  8. Install the timing chain onto the crankshaft sprocket. Align the (dark) link of the timing chain with the timing mark on the crankshaft sprocket (2).
  9. Important: It may be necessary to remove J 44221 to rotate and hold the camshaft (hex) to align the pin to the camshaft sprocket.

  10. Install the intake camshaft sprocket onto the intake camshaft.

  11. Object Number: 748325  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  12. Install the intake camshaft sprocket washer and new bolt.
  13. Tighten

        • Tighten the new intake camshaft sprocket bolt the first pass to 20 N·m (15 lb ft).
        • Use J 45059 to tighten the intake camshaft sprocket bolt the final pass an additional 100 degrees.

    Object Number: 637782  Size: SH
  14. Install the exhaust camshaft actuator into the timing chain.
  15. Align the (dark) link of the timing chain with the timing mark on the exhaust camshaft actuator (1).
  16. Important: It may be necessary to remove J 44221 to rotate and hold the camshaft (hex) to align the pin to the camshaft sprocket.

  17. Install the exhaust camshaft actuator onto the exhaust camshaft.
  18. Notice: The camshaft actuator must be fully advanced during installation. Engine damage may occur if the camshaft actuator is not fully advanced.

    Important: Rotate the camshaft actuator clockwise relative to the camshaft prior to tightening the bolt.

  19. Install the new exhaust camshaft actuator bolt.
  20. Tighten

        • Tighten the new exhaust camshaft actuator bolt the first pass to 25 N·m (18 lb ft).
        • Use J 45059 to tighten the exhaust camshaft actuator bolt the final pass an additional 135 degrees.
  21. Unlock the tensioner.
  22. Remove J 44221 .

  23. Object Number: 748329  Size: SH

    Important: Rotate the camshaft actuator clockwise relative to the camshaft prior to tightening the bolt.

  24. Rotate the camshaft actuator clockwise (as seen from the front of the vehicle).

  25. Object Number: 898509  Size: SH
  26. The dark links (1) on the chain should be aligned with marks on sprockets as shown.

  27. Object Number: 637766  Size: SH
  28. Install the top chain guide.
  29. Add threadlock GM P/N United States 12345498, GM P/N Canada 10953488 to the top chain guide bolt threads.
  30. Install the top chain guide bolts.
  31. Tighten
    Tighten the top chain guide bolts to 10 N·m ( 89 lb in).