Camshaft Timing Chain and Tensioner Removal (LAF, LEA, or LUK)

Special Tools 

EN-48953  Camshaft Actuator Locking Tool

For equivalent regional tools, refer to Special Tools .

Fig 1: View Locking Tool
Courtesy of GENERAL MOTORS COMPANY
1. Rotate the crankshaft to install EN-48953  locking tool (1).
NOTE:

Marking the chain and actuators is crucial to procedures operation. The camshaft actuator and timing chain must have oil removed from the surface prior to marking both actuators and chain.

2. Install EN-48953  locking tool onto the cylinder head and tighten to 10 N.m (89 lb in). If the intake camshaft actuator is moving independent of cam and is not locked, rotate the intake camshaft counterclockwise and the tool will hold the actuator, locking the actuator to the cam.
3. Loosen the intake camshaft actuator bolt.
4. Loosen the exhaust camshaft actuator bolt.
5. Remove EN-48953  locking tool.
Fig 2: View of Timing Chain and Tensioner
Courtesy of GENERAL MOTORS COMPANY
6. Remove the upper timing chain guide bolts.
7. Remove the upper timing chain guide (1).
Fig 3: Identifying Timing Chain Tensioner Plunger
Courtesy of GENERAL MOTORS COMPANY
NOTE:

The timing chain tensioner must be removed to unload chain tension before the timing chain is removed.

8. Remove the timing chain tensioner plunger (1).
Fig 4: Identifying Exhaust Camshaft Actuator
Courtesy of GENERAL MOTORS COMPANY
9. Locate hex on the exhaust camshaft and hold with a wrench (2).
10. Remove the exhaust camshaft bolt and the exhaust camshaft actuator (1). Discard the bolt.
Fig 5: View of Adjustable Timing Chain Guide Bolt.
Courtesy of GENERAL MOTORS COMPANY
11. Remove the adjustable timing chain guide bolt.
12. Remove the adjustable timing chain guide (1).
Fig 6: Identifying Fixed Timing Chain Guide Bolt Plug
Courtesy of GENERAL MOTORS COMPANY
13. Remove the plug (1) to gain access to the fixed timing chain guide bolt.
Fig 7: View of Fixed Timing Chain Guide
Courtesy of GENERAL MOTORS COMPANY
14. Remove the fixed timing chain guide bolts.
15. Remove the fixed timing chain guide (1).
Fig 8: Identifying Intake Camshaft Actuator & Timing Chain
Courtesy of GENERAL MOTORS COMPANY
16. Locate hex on the intake camshaft and hold with a wrench.
17. Remove the intake camshaft actuator bolt, the intake camshaft actuator (1) and the timing chain (2) through the top of the cylinder head. Discard the bolt.
Fig 9: Camshaft Notches
Courtesy of GENERAL MOTORS COMPANY
NOTE:
• The number 3 exhaust valves are open.
• Note the position and direction of the camshafts before removal. Mark the cylinder head in relation to the locking notches before component removal.
18. Mark the cylinder head where the exhaust camshaft actuator locking notch (1) and intake camshaft locking notch (2) are lined up with the cylinder head.
Fig 10: View Of Crankshaft Sprocket
Courtesy of GENERAL MOTORS COMPANY
19. Remove the crankshaft sprocket (2) and friction washers (1), if equipped.
Fig 11: View of Timing Chain Oil Nozzle
Courtesy of GENERAL MOTORS COMPANY
20. Remove the timing chain oil nozzle bolt.
21. Remove the timing chain oil nozzle (1).