GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39946 Crankshaft Rotation Socket

Removal Procedure

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

  2. Object Number: 517185  Size: SH
  3. Align the primary timing marks (1) using the J 39946 .

  4. Object Number: 749349  Size: SH
  5. Install a engine front cover bolt (2) into the front of the engine.
  6. Important: Securing the right secondary camshaft drive chain shoe will prevent the right camshaft drive sprocket teeth from skipping on the right secondary timing chain.

  7. Wrap mechanics wire (1) tightly around both the right secondary camshaft drive chain shoe (3) and the front cover bolt (2).

  8. Object Number: 212695  Size: SH
  9. Remove the two bolts attaching the right secondary camshaft drive chain tensioner to the engine block.
  10. Remove the right secondary camshaft drive chain tensioner, allowing the tensioner to expand as you remove it.
  11. Clean and inspect the camshaft timing drive components. Refer to Camshaft Timing Drive Components Cleaning and Inspection .

Installation Procedure


    Object Number: 749346  Size: SH
  1. Collapse the right secondary camshaft chain tensioner using the following procedure:
  2. 1.1. Rotate the ratchet release lever (2) counterclockwise and hold.
    1.2. Collapse the tensioner shoe (1) and hold.
    1.3. Release the ratchet lever (2).
  3. Slowly release the pressure on the shoe (1), until the ratchet lever (2) moves to the first detent and a "click" is heard and felt.
  4. Collapse the tensioner shoe (1) and hold.

  5. Object Number: 749348  Size: SH
  6. Insert a pin through the hole in the release lever in order to lock the tensioner shoe in the collapsed position.

  7. Object Number: 212695  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.

    Important: Ensure the tensioner release lever is facing outward.

  8. Install the right secondary camshaft drive chain tensioner and retaining bolts.
  9. Tighten
    Tighten the secondary camshaft drive chain tensioner bolts to 25 N·m (18 lb ft).

  10. Remove the pin holding the tensioner to tighten any slack in the timing chain.

  11. Object Number: 749349  Size: SH
  12. Remove the mechanics wire (1) supporting the right secondary camshaft drive chain shoe (3).
  13. Remove the engine front cover bolt (2) from the front of the engine.
  14. Install the engine front cover. Refer to Engine Front Cover Replacement .