GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • J 44221 Camshaft Holding Tool
    • J 45059 Angle Meter

For equivalent regional tools, refer to Special Tools


    Object Number: 1876727  Size: SH
  1. Install J 44221 tool 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 dead 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. Note: It may be necessary to remove J 44221 tool 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. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 1875405  Size: SH
  12. Install the intake camshaft sprocket washer and new bolt.
  13. 9.1. Tighten the new intake camshaft sprocket bolt the first pass to 20 N·m (15 lb ft).
    9.2. Use J 45059 meter to tighten the intake camshaft sprocket bolt the final pass an additional 100 degrees.

    Object Number: 1875406  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. Note: It may be necessary to remove J 44221 tool 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. Object Number: 1875375  Size: SH

    Caution: The camshaft actuator must be fully advanced during installation. Engine damage may occur if the camshaft actuator is not fully advanced.

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

  19. Rotate the camshaft actuator clockwise (as seen from the front of the vehicle).
  20. Unlock the tensioner.
  21. Remove J 44221 tool .

  22. Object Number: 1875408  Size: SH
  23. The dark links (1) on the chain should be aligned with marks on sprockets as shown.

  24. Object Number: 858172  Size: SH
  25. Lube the exhaust camshaft position sensor bore with clean engine oil.
  26. Install and seat the exhaust camshaft position sensor.
  27. Install the exhaust camshaft position sensor bolt and tighten to 10 N·m (89 lb in).