GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39946 Crankshaft Socket - 4.0L and 4.6L

Removal Procedure

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

  2. Object Number: 517185  Size: SH

    Important: Aligning the primary timing marks will locate the left camshafts in a neutral position, preventing them from rotating when the tensioner is removed.

  3. Align the primary timing marks (1) using the J 39946 .

  4. Object Number: 685353  Size: SH
  5. Remove the 2 bolts attaching the left secondary camshaft drive chain tensioner to the engine block.
  6. Remove the left secondary camshaft drive chain tensioner, allowing the tensioner to expand as you remove it.
  7. 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 left 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: 685353  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 left 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. Install the engine front cover. Refer to Engine Front Cover Replacement .