Timing Chain and Sprockets Installation

Tools Required

• J 44221  Camshaft Holding Tool
• J 36660-A  Torque/Angle Meter

1. Install J 44221 with the camshaft flats up and the number 1 cylinder at top dead center.
Fig 1: Installing J 44221 With Camshaft Flats Up And Number 1 Cylinder At Top Dead Center
Courtesy of GENERAL MOTORS CORP.
2. Compress the tensioner and lock in place.
3. Install the crankshaft sprocket.
4. Install the intake camshaft sprocket into the timing chain.
5. Align the (dark) link of the timing chain with the timing mark on the intake camshaft sprocket (1).
6. Feed the timing chain down through the opening in the head.
7. Install the timing chain onto the crankshaft sprocket. Align the (dark) link of the timing chain with the timing mark on the crankshaft sprocket (2).
   IMPORTANT: It may be necessary to remove J 44221 to rotate and hold the camshaft (hex) to align the pin to the camshaft sprocket.
8. Install the intake camshaft sprocket onto the intake camshaft.
Fig 2: Installing Timing Chain Onto The Crankshaft Sprocket
Courtesy of GENERAL MOTORS CORP.
9. Install the intake camshaft sprocket washer and new bolt.
   NOTE: 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.

   Tighten 

   • Tighten the new intake camshaft sprocket bolt the first pass to 20 N.m (15 lb ft).
   • Use J 36660-A to tighten the intake camshaft sprocket bolt the final pass an additional 100 degrees.
Fig 3: Installing Intake Camshaft Sprocket Washer And New Bolt
Courtesy of GENERAL MOTORS CORP.
10. Install the exhaust camshaft actuator into the timing chain.
11. Align the (dark) link of the timing chain with the timing mark on the exhaust camshaft actuator (1).
    IMPORTANT: It may be necessary to remove J 44221 to rotate and hold the camshaft (hex) to align the pin to the camshaft sprocket.
Fig 4: Aligning (Dark) Link Of Timing Chain With Timing Mark On Exhaust Camshaft Actuator
Courtesy of GENERAL MOTORS CORP.
12. Install the exhaust camshaft actuator onto the exhaust camshaft.
    NOTE: The camshaft actuator must be fully advanced during installation. Engine damage may occur if the camshaft actuator is not fully advanced.
13. Install the new exhaust camshaft actuator bolt.

    Tighten 

    • Tighten the new exhaust camshaft actuator bolt the first pass to 25 N.m (18 lb ft).
    • Use J 36660-A to tighten the exhaust camshaft actuator bolt the final pass an additional 135 degrees.
14. Unlock the tensioner.
15. Remove J 44221.
    IMPORTANT: Rotate the camshaft actuator clockwise relative to the camshaft prior to tightening the bolt.
16. Rotate the camshaft actuator clockwise (as seen from the front of the vehicle).
Fig 5: Rotating Camshaft Actuator Clockwise
Courtesy of GENERAL MOTORS CORP.
17. The dark links (1) on the chain should be aligned with marks on sprockets as shown.
Fig 6: Aligning Dark Links On Chain With Marks On Sprockets
Courtesy of GENERAL MOTORS CORP.
18. Install the top chain guide.
19. Add threadlock GM P/N United States 12345498, GM P/N Canada 10953488 to the top chain guide bolt threads.
20. Install the top chain guide bolts.

    Tighten 

    Tighten the top chain guide bolts to 10 N.m (89 lb in).

Fig 7: Installing Top Chain Guide Bolts
Courtesy of GENERAL MOTORS CORP.