Tools Required

1. Install J 44221 with the camshaft flats up and the number 1 cylinder at top dead center. The crankshaft pin should be at 12 o'clock when the number 1 piston is at top dead center.



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 temporarily 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.




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.

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.




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 temporarily remove J 44221 to rotate and hold the camshaft (hex) to align the pin to the camshaft sprocket.

12. Install the exhaust camshaft actuator onto the exhaust camshaft.
13. Install the exhaust camshaft actuator bolt.

Tighten

•	Tighten the 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.

14. Unlock the tensioner.
15. Remove J 44221 .



16. The dark links (1) on the chain should be aligned with marks on sprockets as shown.



17. Install the top chain guide.
18. Add threadlock GM P/N 12378521 (Canadian P/N 88901148) to the top chain guide bolt threads.
19. Install the top chain guide bolts.

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




20. Lube the exhaust camshaft position sensor bore with clean engine oil.
21. Install and seat the exhaust camshaft position sensor.
22. Install the exhaust camshaft position sensor bolt.

Tighten
Tighten the exhaust camshaft position sensor bolt to 10 N·m (89 lb in).