GM Service Manual Online
For 1990-2009 cars only

Camshaft Drive Chain Tensioner Replacement Primary

Removal Procedure

Tools Required

J 42038 Camshaft Holding Fixture

  1. Remove the camshaft covers. Refer to Camshaft Cover Replacement .
  2. Install the J 42038 to the camshafts on the left (front) and right (rear) cylinder heads.
  3. Remove the engine front cover. Refer to Engine Front Cover Replacement

  4. Object Number: 235192  Size: SH
  5. Loosen both primary timing chain tensioner bolts.
  6. Remove the lower primary timing chain tensioner bolt allowing the tensioner to swing downward and expand. This will release tension on the primary drive chain.
  7. Remove the upper tensioner bolt.
  8. Remove the primary drive chain tensioner (1).

Installation Procedure

Tools Required

J 42038 Camshaft Holding Fixture


    Object Number: 240843  Size: SH
  1. Collapse the primary timing 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 and slowly release the pressure on the shoe.
  3. As the ratchet lever moves to its first click, hold the tensioner shoe inward. Insert a pin through the hole in the release lever.
  4. The locked ratchet mechanism should hold the shoe in a collapsed position.

  5. Object Number: 235192  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: Make sure the tensioner release lever faces toward you before tightening.

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


    Object Number: 263904  Size: SH
  8. Make sure all the timing marks are properly aligned. Make adjustments as necessary.
  9. Remove the pin holding the tensioner to tighten any slack in the timing chain.
  10. Remove the J 42038 from the camshafts on the left (front) and right (rear) cylinder heads.
  11. Verify correct timing chain and timing mark alignments.
  12. Install the camshaft covers. Refer to Camshaft Cover Replacement .
  13. Install the engine front cover. Refer to Engine Front Cover Replacement

Camshaft Drive Chain Tensioner Replacement Secondary Left Front

Removal Procedure

Tools Required

    • J 42038 Camshaft Holding Fixture
    • J 42042 Timing Chain/Sprocket Holding Fixture
  1. Partially drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Disconnect the thermostat housing for J 42042 access. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.
  3. Remove the left (front) camshaft cover. Refer to Camshaft Cover Replacement .

  4. Object Number: 539986  Size: SH
  5. Install the J 42038 on to the left (front) camshafts.
  6. Remove the camshaft sprocket bolts.

  7. Object Number: 423243  Size: SH
  8. Install the J 42042 on to the left (front) cylinder head.
  9. Evenly slide the secondary drive chain and camshaft sprockets off the camshafts on to the J 42042 .

  10. Object Number: 234529  Size: SH
  11. Remove the secondary drive chain tensioner retaining bolts.
  12. Remove the secondary drive tensioner.

Installation Procedure

Tools Required

    • J 36660-A Electronic Torque Angle Meter
    • J 42038 Camshaft Holding Fixture
    • J 42042 Timing Chain/Sprocket Holding Fixture

    Object Number: 234529  Size: SH
  1. Position the secondary timing chain tensioner between the camshafts.
  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.

  3. Install the secondary timing chain tensioner bolts.
  4. Tighten
    Tighten the secondary timing chain tensioner bolts to 12 N·m (106 lb in).


    Object Number: 482996  Size: SH
  5. Once mounted, compress the secondary timing chain tensioner shoes with your hand.
  6. Lock the tensioner by inserting a piece of wire (2) into the access hole in the side of the tensioner (1).
  7. Slowly release pressure on the tensioner shoes. The tensioner should remain compressed.

  8. Object Number: 287924  Size: SH
  9. Slide the intake and exhaust camshaft sprockets off of the J 42042 and onto their respective camshafts and align the drive pins (1) in the camshafts.

  10. Object Number: 423243  Size: SH
  11. Remove the J 42042 from the left (front) cylinder head.
  12. Install the intake camshaft sprocket retaining bolt and exhaust camshaft sprocket retaining bolt.
  13. Tighten
    Tighten the camshaft sprocket retaining bolts to 25 N·m+ 45 degrees (18 lb ft + 45 degrees) using the J 36660-A .

  14. Remove the locking wire from the secondary timing chain tensioner allowing the tensioner shoes to expand and apply pressure to the timing chain.

  15. Object Number: 539986  Size: SH
  16. Remove the J 42038 from the left (front) camshafts.
  17. Install the left (front) camshaft cover. Refer to Camshaft Cover Replacement .
  18. Install the thermostat housing. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.
  19. Fill the cooling system with engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.

Camshaft Drive Chain Tensioner Replacement Secondary Right Rear

Removal Procedure

Tools Required

    • J 42038 Camshaft Holding Fixture
    • J 42042 Timing Chain/Sprocket Holding Fixture
  1. Remove the right (rear) camshaft cover. Refer to Camshaft Cover Replacement .

  2. Object Number: 423255  Size: SH
  3. Install the J 42038 on to the right (rear) camshafts.
  4. Remove the camshaft position sensor. Refer to Camshaft Position Sensor Replacement in Engine Controls - 3.5L.
  5. Remove the camshaft sprocket bolts.
  6. Install the J 42042 on to the right (rear) cylinder head.
  7. Evenly slide the secondary drive chain and camshaft sprockets off the camshafts on to the J 42042 .

  8. Object Number: 576493  Size: SH
  9. Remove the secondary drive chain tensioner retaining bolts.
  10. Remove the secondary drive tensioner (1).

Installation Procedure

Tools Required

    • J 36660-A Electronic Torque Angle Meter
    • J 42038 Camshaft Holding Fixture
    • J 42042 Timing Chain/Sprocket Holding Fixture

    Object Number: 576493  Size: SH
  1. Position the secondary timing chain tensioner (1) between the camshafts.
  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.

  3. Install the secondary timing chain tensioner bolts.
  4. Tighten
    Tighten the secondary timing chain tensioner bolts to 12 N·m (106 lb in).


    Object Number: 277962  Size: SH
  5. Once mounted, compress the secondary timing chain tensioner shoes with your hand.
  6. Lock the tensioner by inserting a piece of wire (2) into the access hole in the side of the tensioner (1).
  7. Slowly release pressure on the tensioner shoes. The tensioner should remain compressed.

  8. Object Number: 287924  Size: SH
  9. Slide the intake and exhaust camshaft sprockets off of the J 42042 and onto their respective camshafts and align the drive pins (1) in the camshafts.
  10. Remove the J 42042 from the right (rear) cylinder head.
  11. Install the intake camshaft sprocket bolt and exhaust camshaft sprocket bolt.
  12. Tighten

    1. Tighten the camshaft sprocket bolts to 25 N·m (18 lb ft
    2. Use the J 36660-A in order to tighten the camshaft sprocket bolts an additional 45 degrees.
  13. Remove the locking wire from the secondary timing chain tensioner allowing the tensioner shoes to expand and apply pressure to the timing chain.

  14. Object Number: 423255  Size: SH
  15. Remove the J 42038 from the right (rear) camshafts.
  16. Install the camshaft position sensor. Refer to Camshaft Position Sensor Replacement in Engine Controls - 3.5L.
  17. Install the right (rear) camshaft cover. Refer to Camshaft Cover Replacement .