GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 520268  Size: SH
  1. Disconnect both the battery negative cables from the batteries. Refer to Battery Replacement in Engine Electrical.
  2. Rotate the engine to TDC.
  3. Remove the engine front cover from the engine block. Refer to Engine Front Cover Replacement .
  4. Remove the bolt from the timing chain sprocket to the camshaft.

  5. Object Number: 358425  Size: SH
  6. Remove the fuel injection pump drive gear from the camshaft.

  7. Object Number: 59876  Size: SH
  8. Remove the timing chain and sprocket from the camshaft.

  9. Object Number: 59879  Size: SH
  10. Remove the sprocket from the crankshaft.
  11. Replace the wood drift key if damaged.

Installation Procedure


    Object Number: 59879  Size: SH
  1. Install the crankshaft sprocket on the crankshaft.

  2. Object Number: 59876  Size: SH

    Important: Make sure the timing marks are aligned.

  3. Install the camshaft sprocket with the timing chain to the engine block.

  4. Object Number: 358425  Size: SH
  5. Install the fuel injection pump drive gear to the camshaft.

  6. Object Number: 520268  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.

  7. Install the bolts from the timing chain sprocket to the camshaft.
  8. Tighten
    Tighten the bolts to 170 N·m (125 lb ft).

  9. Install the engine front cover to the engine block. Refer to Engine Front Cover Replacement .
  10. Connect both the battery negative cables to the batteries. Refer to Battery Replacement in Engine Electrical.
  11. Perform the TDC off set timing procedure. Refer to Fuel Injection Pump Top Dead Center Offset Adjustment in Engine Controls-6.5L-L65.