56. Timing Chain, Sprockets, Tensioner Installation

Timing Chain, Sprockets, Tensioner Installation

Tools Required

J 45059 Angle Meter




1. Install the timing chain drive sprocket to the crankshaft with the timing mark in the 5 o'clock position.





Important:
^ There are 3 colored links on the timing chain. Two links are of matching color, and one link is of a unique color. Use the following procedure to line up the links with the actuators. Orient the chain so that the colored links are visible.

^ Always use new actuator bolts.

Assemble the intake camshaft actuator into the timing chain with the timing mark lined up with the uniquely colored link (1). Hand tighten a new intake camshaft actuator bolt.




2. Lower the timing chain through the opening in the cylinder head. Use care to ensure that the chain goes around both sides of the cylinder block bosses (1, 2).




3. Route the timing chain around the crankshaft sprocket and line up the first matching colored link (2) with the timing mark on the crankshaft sprocket, in approximately the 5 o'clock position.





Notice: Refer to Fastener Notice.

4. Install the adjustable timing chain guide through the opening in the cylinder head and install the adjustable timing chain bolt.

Tighten the adjustable timing chain guide bolt to 10 N.m (89 lb in).





Important: Always install NEW actuator bolts.

5. Install the exhaust camshaft actuator and a NEW bolt loosely onto the exhaust camshaft.




6. Align the timing mark on the actuator with the last matching colored link (3). Install the bolt finger tight.





Notice: Do not rotate either camshaft more than half turn in either direction with crankshaft at top dead center (TDC). To do so may cause valve to piston contact resulting in a damaged valve and/or a damaged piston.

7. If the camshaft is 180 degrees out of time, use the following procedure to re-align the cam.
Using a 24 mm wrench, first turn the intake camshaft until the alignment feature on the back of the camshaft actuator seats in the notch in the front of the intake camshaft.
1. Turn the crankshaft 45 degrees in either direction.
2. Turn the intake cam to the appropriate location.
3. Turn the crankshaft back to top dead center.
8. When the actuator seats on the cam, tighten the sprocket bolt hand tight.
9. Verify that all of the colored links and the appropriate timing marks are still aligned. If they are not, repeat the portion of the procedure necessary to align the timing marks.




10. Install the fixed timing chain guide and bolts.

Tighten the fixed timing chain guide bolts to 15 N.m (11 lb ft).




11. Install the upper timing chain guide and bolts.

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




12. Using a 24 mm wrench, engage the hex on the intake camshaft and using a torque wrench, tighten the camshaft actuator bolt.

Tighten the intake camshaft position actuator bolt to 30 N.m (22 lb ft), plus 100 degrees using the J45059.

13. Using a 24 mm wrench, engage the hex on the exhaust camshaft and using a torque wrench, tighten the camshaft actuator bolt.

Tighten the exhaust camshaft position actuator bolt to 30 N.m (22 lb ft), plus 100 degrees using the J45059.




14. Inspect the timing chain tensioner seal for damage. If damaged, replace the seal.




15. Inspect to ensure all dirt and debris is removed from the timing chain tensioner threaded hole in the cylinder head.

Important: Make sure the timing chain tensioner seal is centered throughout the torque procedure to eliminate the possibility of an oil leak.

16. Install the new timing chain tensioner assembly.

Tighten the timing chain tensioner to 75 N.m (55 lb ft).

17. The timing chain tensioner is released by compressing it 2 mm (0.079 in) which will release the locking mechanism in the ratchet. To release the timing chain tensioner, use a suitable tool with a rubber tip on the end. Feed the tool down through the cam drive chest to rest on the cam chain. Then give a sharp jolt diagonally downwards to release the tensioner.




18. Install the timing chain oiling nozzle.

Tighten the timing chain oiling nozzle bolt to 10 N.m (89 lb in).




19. Apply sealant GM P/N 12345382 (Canadian P/N 10953489) compound to the thread, and install the timing chain guide bolt access hole plug.

Tighten the access hole plug to 90 N.m (66 lb ft).