Timing Chain And Sprockets Installation

Tools Required

• J 44221  Camshaft Holding Tool. See Special Tools and Equipment .
• J 45059  Angle Meter. See Special Tools and Equipment .

Fig 1: Installing J 44221
Courtesy of GENERAL MOTORS CORP.
1. Install J 44221  with the camshaft flats up and the number 1 cylinder at top dead center. See Special Tools and Equipment . The crankshaft pin should be at 12 o'clock when the number 1 piston is at top dead center.
Fig 2: Installing Timing Chain & Sprockets
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. See Special Tools and Equipment .
8. Install the intake camshaft sprocket onto the intake camshaft.
Fig 3: Installing Intake Camshaft Sprocket Washer & Bolt
Courtesy of GENERAL MOTORS CORP.
NOTE: Refer to Fastener Notice in Cautions and Notices.
9. Install the intake camshaft sprocket washer and new bolt.

   Tighten: 

   • Tighten the new intake camshaft sprocket bolt the first pass to 20 N.m (15 lb ft).
   • Use J 45059  to tighten the intake camshaft sprocket bolt the final pass an additional 100 degrees. See Special Tools and Equipment .

Fig 4: Aligning Exhaust Camshaft Position Actuator
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. See Special Tools and Equipment .
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.
IMPORTANT: Rotate the camshaft actuator clockwise relative to the camshaft prior to tightening the bolt.
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 45059  to tighten the exhaust camshaft actuator bolt the final pass an additional 135 degrees. See Special Tools and Equipment .

14. Unlock the tensioner.
15. Remove J 44221  . See Special Tools and Equipment .
Fig 5: Identifying Camshaft Position Actuator
Courtesy of GENERAL MOTORS CORP.
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 6: Identifying Cam Chain Timing Marks
Courtesy of GENERAL MOTORS CORP.
17. The dark links (1) on the chain should be aligned with marks on sprockets as shown.
Fig 7: View Of top Chain Guide
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).