GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Remove the front cover. Refer to Engine Front Cover Replacement .
  2. Remove the required camshaft covers. Refer to Camshaft Cover Replacement (Left) and Camshaft Cover Replacement (Right) .
  3. Loosen both of the drive chain tensioner bolts.
  4. Remove the tensioner bolts and the tensioner allowing the tensioner to expand as you remove it.

  5. Object Number: 53648  Size: SH
  6. Remove the chain guide access plugs located in the cylinder heads. Note the O-ring seal on each access plug.
  7. Remove the camshaft position sensor.

  8. Object Number: 53005  Size: SH
  9. Remove the secondary chain guide retaining bolts.
  10. Remove the secondary chain guides.

  11. Object Number: 53645  Size: SH
  12. Remove the camshaft sprocket retaining bolts.

  13. Object Number: 53644  Size: SH
  14. Slide the camshaft sprockets off of the camshafts.
  15. Remove the camshaft sprockets and the secondary drive chain together. Leave the intermediate sprocket in place.

Installation Procedure

  1. Retime the camshafts. Refer to Setting Camshaft Timing .
  2. Install the engine front cover. Refer to Engine Front Cover Replacement .

  3. Object Number: 52981  Size: SH
  4. Install the accessory drive belt idler pulley (3).
  5. Install the accessory drive belt idler pulley retainer bolt.
  6. Tighten
    Tighten the accessory drive belt idler pulley retainer bolt to 50 N·m (37 lb ft).

    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 accessory drive belt tensioner (6).
  8. Install the accessory drive belt tensioner bolt.
  9. Tighten
    Tighten the accessory drive belt tensioner bolt to 50 N·m (37 lb ft).

  10. Install the accessory drive belt. Refer to Drive Belt Replacement .
  11. Install the camshaft covers. Refer to Camshaft Cover Replacement (Left) and Camshaft Cover Replacement (Right) .