GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 520268  Size: SH
  1. Disconnect the battery negative cables from the batteries. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  2. Remove the air cleaner assembly from the vehicle. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L.
  3. Remove the surge tank from the vehicle. Refer to Surge Tank (Diesel) Replacement in Engine Cooling.
  4. Remove the engine front cover from the engine block. Refer to Engine Front Cover Replacement .
  5. Remove the bolt from the timing chain sprocket to the camshaft.

  6. Object Number: 358425  Size: SH
  7. Remove the fuel injection pump drive gear from the timing chain sprocket.

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

  10. Object Number: 59879  Size: SH
  11. Remove the sprocket from the crankshaft.
  12. Important: Replace the wood drift key if there are signs of excessive wear or damage. Do not try to repair the wood drift key.

  13. Remove the wood drift key if damaged from the camshaft.

Installation Procedure

Notice: Perform TDC Offset Recovery procedure if the timing chain, timing gears, engine front cover, crankshaft position sensor, crankshaft or other components affecting the timing are replaced.


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

  2. Object Number: 11503  Size: SH
  3. Align the timing marks.

  4. Object Number: 59876  Size: SH
  5. Install the camshaft sprocket with the timing chain.

  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 timing chain sprocket bolt to the camshaft.
  8. Tighten
    Tighten the bolt to 171 N·m (125 lb ft).

  9. Install the engine front cover to the engine block. Refer to Engine Front Cover Replacement .

  10. Object Number: 346972  Size: SH
  11. Install the fuel injection pump drive gear to the camshaft.
  12. Tighten
    Tighten the bolts to 25 N·m (20 lb ft).

  13. Install the surge tank in the vehicle. Refer to Surge Tank (Diesel) Replacement in Engine Cooling.
  14. Install the air cleaner assembly in the vehicle. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L.
  15. Connect the battery negative cables to the batteries. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  16. Perform TDC offset timing adjustment. Refer to Fuel Injection Pump Top Dead Center Offset Adjustment in Engine Controls-6.5L.