GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 338441  Size: SH
  1. Remove the engine assembly, refer to Engine Replacement .
  2. Remove the accessory drive belt. Refer to Drive Belt Replacement .
  3. Remove the accessory drive belt idler pulley.

  4. Object Number: 205559  Size: SH
  5. Remove the accessory drive belt tensioner.
  6. Remove the front cover. Refer to Engine Front Cover Replacement .
  7. Remove the oil pump. Refer to Oil Pump Replacement .
  8. Remove the left side cam cover. Refer to Camshaft Cover Replacement .
  9. Remove the right side cam cover. Refer to Camshaft Cover Replacement .

  10. Object Number: 207540  Size: SH
  11. Align all timing marks (1).

  12. Object Number: 210241  Size: SH
  13. Remove the intermediate sprocket retaining bolt.
  14. Remove the primary drive chain tensioner.

  15. Object Number: 207533  Size: SH
  16. Remove the primary drive chain guide (1).

  17. Object Number: 207537  Size: SH
  18. Remove the primary chain drive sprocket, the primary chain (3) and the intermediate sprocket as an assembly.
  19. Remove the secondary drive chains from around the intermediate shaft sprocket.

  20. Object Number: 207544  Size: SH
  21. Remove the intermediate sprocket shaft retaining bolts.
  22. Remove the intermediate sprocket shaft (1).
  23. Slide the gears and the primary drive chain off of the crankshaft and the intermediate shaft.
  24. Important: The intermediate shaft should not be removed unless wear is evident.

Installation Procedure

Tools Required

J 39946 Crankshaft Rotation Socket


    Object Number: 207544  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.

  1. Install the intermediate sprocket shaft (1) and the retaining bolts.
  2. Tighten
    Tighten the intermediate sprocket shaft bolts to 10 N·m (89 lb in).


    Object Number: 207540  Size: SH
  3. Align the timing marks (1) of the intermediate and crankshaft sprockets. The marks should be aligned vertically in the installed position.
  4. Install the primary timing chain on the drive sprockets.
  5. Make sure that the piston number one is at top dead center (TDC) and the crankshaft keyway is approximately at the one o'clock position.

  6. Object Number: 207537  Size: SH
  7. Install the primary timing chain (3), intermediate sprocket and crankshaft sprocket as an assembly onto their respective shafts (2 and 4). Use the J 39946 to align the crankshaft key (1) with the drive sprocket.
  8. Install the intermediate sprocket retaining bolt.
  9. Tighten
    Tighten the intermediate sprocket shaft bolt to 60 N·m (44 lb ft).


    Object Number: 53004  Size: SH
  10. Collapse the primary timing chain tensioner using the following procedure:
  11. 7.1. Rotate the ratchet release lever counterclockwise and hold.
    7.2. Collapse the tensioner shoe and hold.
    7.3. Release the ratchet lever and slowly release the pressure on the shoe.

    Object Number: 52989  Size: SH
  12. As the ratchet lever moves to its first click, hold the tensioner shoe inward. Insert a pin through the hole in the release lever. The locked ratchet mechanism should hold the shoe in a collapsed position.

  13. Object Number: 207533  Size: SH
  14. Install the primary timing chain guide (1) and retaining bolts.
  15. Tighten
    Tighten the primary timing chain guide bolts to 25 N·m (18 lb ft).


    Object Number: 210241  Size: SH

    Important: Make sure the tensioner release lever faces toward you before tightening.

  16. Install the primary timing chain tensioner and retaining bolts.
  17. Tighten
    Tighten the primary timing chain tensioner bolts to 25 N·m (18 lb ft).


    Object Number: 207540  Size: SH
  18. Make sure the timing marks are aligned vertically.
  19. Important: DO NOT remove the pin holding the tensioner until the secondary timing chains are installed.

  20. Install the oil pump. Refer to Oil Pump Replacement .
  21. Install the left side cam cover. Refer to Camshaft Cover Replacement .
  22. Install the right side cam cover. Refer to Camshaft Cover Replacement .

  23. Object Number: 338441  Size: SH
  24. Install the accessory drive belt idler pulley.
  25. Install the accessory drive belt tensioner.
  26. Install the accessory drive belt. Refer to Drive Belt Replacement .
  27. Install the engine assembly. Refer to Engine Replacement .