Tools Required

J 39579 Camshaft Sprocket Wrench.

Important: Ensure that the alignment dowel pins are in the cylinder block and the timing chain housing, before installing the timing chain housing. The dowel pins ensure proper chain housing and front cover location for correct front oil seal-to-crankshaft alignment.




1. Install the timing chain housing gaskets. Gaskets are reusable.
2. Install the timing chain housing. No sealer is needed.
3. Install the timing chain housing to the camshaft housing bolts and hand tighten.
4. Install the timing chain housing to the block fasteners and hand tighten.
5. Install the chain housing to the oil pan bolts and hand tighten.



6. Tighten the bolts.

Tighten

•	(1) (M8 X 1.25 X 25) to 26 N·m (19 lb ft).

•	(2) (M10 X 1.25 X 55) to 50 N·m (37 lb ft).

•	(3) (M8 X 1.25 X 25) to 29 N·m (21 lb ft).

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.




7. Install the camshaft sprockets. Sprockets are identical and interchangeable.
8. Clean the old sealer off of the bolt with a wire brush.
9. Clean the threaded hole in the camshaft with a nylon bristle brush.
10. Install the camshaft sprocket bolts and washers while holding the sprockets with J 39579 .

Tighten
Tighten the bolts to 70 N·m (52 lb ft).

11. Use Adhesive/Sealant Compound GM P/N 12345493 or equivalent on the camshaft sprocket bolts.