GM Service Manual Online
For 1990-2009 cars only

Camshaft Timing Chain and Sprocket Replacement First Design

Tools Required

    • J 8433 Two Jaw Puller
    • J 41816-2 Crankshaft End Protector
    • J 41558 Crankshaft Sprocket Remover
    • J 41665 Crankshaft Balancer and Sprocket Installer

Removal Procedure


    Object Number: 1402055  Size: SH
  1. Remove the oil pump. Refer to Oil Pump, Screen, and Crankshaft Oil Deflector Replacement .
  2. Rotate the crankshaft until the timing marks on the crankshaft and the camshaft sprockets are aligned.
  3. Notice: Do not turn the crankshaft assembly after the timing chain has been removed in order to prevent damage to the piston assemblies or the valves.

  4. Remove the camshaft sprocket bolts (206) .
  5. Remove the camshaft sprocket (205) and timing chain (208).

  6. Object Number: 1402069  Size: SH
  7. Remove the timing chain dampener (232) and bolts (231).

  8. Object Number: 63189  Size: SH
  9. Using the J 8433 , J 41816-2 and the J 41558 remove the crankshaft sprocket.

  10. Object Number: 1402075  Size: SH
  11. Remove the crankshaft sprocket.

  12. Object Number: 156149  Size: SH
  13. Remove the crankshaft sprocket key, if required.
  14. Clean and inspect the timing chain and sprockets. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection .

Installation Procedure


    Object Number: 156149  Size: SH
  1. Install the key into the crankshaft keyway, if previously removed.

  2. Object Number: 1272887  Size: SH
  3. Tap the key (122) into the keyway until both ends of the key bottom onto the crankshaft.

  4. Object Number: 1402075  Size: SH
  5. Install the crankshaft sprocket onto the front of the crankshaft. Align the crankshaft key with the crankshaft sprocket keyway.

  6. Object Number: 63199  Size: SH
  7. Using the J 41665 , install the crankshaft sprocket onto the crankshaft until fully seated against the crankshaft flange.
  8. Rotate the crankshaft sprocket until the alignment mark is in the 12 o'clock position.
  9. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1402069  Size: SH
  10. Install the timing change guide (232) and bolts (231).
  11. Tighten
    Tighten the bolts to 25 N·m (18 lb ft).


    Object Number: 1402098  Size: SH
  12. With the chain dampener properly installed, the heads of the bolts (231) should install to flush or below the face of the guide (232).

  13. Object Number: 1402055  Size: SH

    Important: 

       • Properly locate the camshaft sprocket locating pin with the camshaft sprocket alignment hole.
       • The sprocket teeth and timing chain must mesh.
       • The camshaft and the crankshaft sprocket alignment marks MUST be aligned properly. Position the camshaft sprocket alignment mark in the 6 o'clock position.

  14. Install the camshaft sprocket (205) and timing chain (208). If necessary, rotate the camshaft or crankshaft sprockets in order to align the timing marks.
  15. Install the camshaft sprocket bolts (206).
  16. Tighten
    Tighten the bolts to 25 N·m (18 lb ft).


    Object Number: 1402101  Size: SH
  17. Inspect the camshaft (1) and crankshaft (2) sprockets for proper timing mark alignment.
  18. Install the oil pump. Refer to Oil Pump, Screen, and Crankshaft Oil Deflector Replacement .