GM Service Manual Online
For 1990-2009 cars only

Camshaft Timing Chain and Sprocket Replacement 3.8L L36

Removal Procedure

  1. Remove the engine front cover. Refer to Engine Front Cover Replacement .

  2. Object Number: 192708  Size: SH
  3. Align the timing marks on the sprockets so that they are as close as possible.

  4. Object Number: 153593  Size: SH
  5. Remove the timing chain dampener.

  6. Object Number: 248088  Size: SH
  7. Remove the camshaft sprocket bolt.

  8. Object Number: 153596  Size: SH
  9. Remove the camshaft sprocket and the timing chain.
  10. Important: If the sprocket does not come off easily, a light blow on the lower edge of the sprocket with a plastic mallet should dislodge the sprocket.

  11. Remove the crankshaft sprocket.

  12. Object Number: 97869  Size: SH
  13. Remove the balance shaft drive gear in order to access the camshaft thrust plate, if required.

  14. Object Number: 190552  Size: SH
  15. Remove the camshaft thrust plate bolts, if required.
  16. Remove the camshaft thrust plate, if required.

  17. Object Number: 97868  Size: SH
  18. Remove the balance shaft driven gear bolt, if required.
  19. Remove the balance shaft driven gear, if required.
  20. Clean and inspect all of the components for wear and/or damage. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection .
  21. If the pistons have been moved in the engine, use the following procedure:
  22. 13.1. Turn the crankshaft so that the number one piston is at top dead center.
    13.2. Turn the camshaft so that, with the sprocket temporarily installed, the timing mark is straight down.

Installation Procedure

Tools Required

J 36660-A Electronic Torque Angle Meter


    Object Number: 97868  Size: SH
  1. Install the balance shaft driven gear, if required.
  2. 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.

    Notice: This bolt is designed to permanently stretch when tightened, and therefore MUST be replaced anytime it is removed. The correct part number fastener must be used to replace this type of fastener. Do not use a bolt that is stronger in this application. If the correct bolt is not used, the parts will not be tightened correctly. The system or the components may be damaged.

  3. Prevent the balance shaft from rotating and install the balance shaft driven gear bolt, if required.
  4. Tighten
    Tighten the balance shaft driven gear bolt to 22 N·m (16 lb ft). Use the J 36660-A in order to rotate the bolts an additional 70 degrees.


    Object Number: 190552  Size: SH
  5. Install the camshaft thrust plate, if required.
  6. Install the camshaft thrust plate bolts, if required.
  7. Tighten
    Tighten the camshaft thrust plate bolts to 15 N·m (11 lb ft).


    Object Number: 97869  Size: SH
  8. Install the balance shaft drive gear, if required.

  9. Object Number: 97752  Size: SH
  10. Align the timing marks on the balance shaft drive gear and the balance shaft driven gear.

  11. Object Number: 153596  Size: SH
  12. Install the crankshaft sprocket.
  13. Install the timing chain and sprocket.

  14. Object Number: 192708  Size: SH
  15. Assemble the timing chain on the sprockets with the timing marks as close together as possible.

  16. Object Number: 248088  Size: SH
  17. Install the camshaft sprocket bolt.
  18. Tighten
    Tighten the camshaft sprocket bolt to 100 N·m (74 lb ft). Use the J 36660-A in order to rotate the bolts an additional 90 degrees.


    Object Number: 153593  Size: SH
  19. Install the timing chain dampener.
  20. Tighten
    Tighten the dampener bolt to 22 N·m (16 lb ft).

    Important: Rotate the engine two revolutions and check the timing marks. Ensure that the marks are aligned.

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

Camshaft Timing Chain and Sprocket Replacement 3.8L L67

Removal Procedure

  1. Remove the engine front cover. Refer to Engine Front Cover Replacement .

  2. Object Number: 36603  Size: SH
  3. Align the timing marks on the sprockets so that they are as close as possible.

  4. Object Number: 153593  Size: SH
  5. Remove the timing chain dampener.

  6. Object Number: 153595  Size: SH
  7. Remove the camshaft sprocket bolt.

  8. Object Number: 248089  Size: SH
  9. Remove the camshaft sprocket and the timing chain.
  10. Important: If the sprocket does not come off easily, a light blow on the lower edge of the sprocket with a plastic mallet should dislodge the sprocket.

  11. Remove the crankshaft sprocket.

  12. Object Number: 97869  Size: SH
  13. Remove the balance shaft drive gear in order to access the camshaft thrust plate.

  14. Object Number: 190552  Size: SH
  15. Remove the camshaft thrust plate bolts.
  16. Remove the camshaft thrust plate.

  17. Object Number: 97868  Size: SH
  18. Remove the balance shaft driven gear bolt.
  19. Remove the balance shaft driven gear.
  20. Clean and inspect all of the components for wear and/or damage. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection .
  21. If the pistons have been moved in the engine, use the following procedure:
  22. 13.1. Turn the crankshaft so that the number one piston is at top dead center.
    13.2. Turn the camshaft so that, with the sprocket temporarily installed, the timing mark is straight down.

Installation Procedure

Tools Required

J 36660-A Electronic Torque Angle Meter


    Object Number: 97868  Size: SH
  1. Install the balance shaft driven gear.
  2. 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.

    Notice: This bolt is designed to permanently stretch when tightened, and therefore MUST be replaced anytime it is removed. The correct part number fastener must be used to replace this type of fastener. Do not use a bolt that is stronger in this application. If the correct bolt is not used, the parts will not be tightened correctly. The system or the components may be damaged.

  3. Prevent the balance shaft from rotating and install the balance shaft driven gear bolt.
  4. Tighten
    Tighten the balance shaft driven gear bolt to 22 N·m (16 lb ft). Use the J 36660-A in order to rotate the bolts an additional 70 degrees.


    Object Number: 190552  Size: SH
  5. Install the camshaft thrust plate.
  6. Install the camshaft thrust plate bolts.
  7. Tighten
    Tighten the camshaft thrust plate bolts to 15 N·m (11 lb ft).


    Object Number: 97869  Size: SH
  8. Install the balance shaft drive gear.

  9. Object Number: 97752  Size: SH
  10. Align the timing marks on the balance shaft drive gear and the balance shaft driven gear.

  11. Object Number: 248089  Size: SH
  12. Install the crankshaft sprocket.
  13. Install the timing chain and sprocket.

  14. Object Number: 36603  Size: SH
  15. Assemble the timing chain on the sprockets with the timing marks as close together as possible.

  16. Object Number: 153595  Size: SH
  17. Install the camshaft sprocket bolt.
  18. Tighten
    Tighten the camshaft sprocket bolt to 100 N·m (74 lb ft). Use the J 36660-A in order to rotate the bolts an additional 90 degrees.


    Object Number: 153593  Size: SH
  19. Install the timing chain dampener.
  20. Tighten
    Tighten the dampener bolt to 22 N·m (16 lb ft).

    Important: Rotate the engine two revolutions and check the timing marks. Ensure that the marks are aligned.

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