For 1990-2009 cars

### Removal Procedure

#### Tools Required

J 5825-A Crankshaft Sprocket Remover

1. Remove the engine front cover. Refer to Engine Front Cover Replacement .
2. Rotate the crankshaft until the timing marks in the following locations are aligned:

• | The camshaft alignment pin (1).

• | The timing chain dampener (2) to the crankshaft sprocket (3).

• | The crankshaft key (4).

• | The timing chain dampener (5) to the camshaft sprocket locator hole (6).

3. Remove the camshaft sprocket bolt.
4. Remove the camshaft sprocket.
5. Remove the timing chain.
6. Use the J 5825-A in order to remove the crankshaft sprocket.
7. Remove the timing chain dampener bolts.
8. Remove the timing chain dampener.
9. If necessary remove the camshaft thrust plate bolts.
10. Remove the camshaft thrust plate.
11. Clean and inspect the timing chain and gears. Refer to Timing Chain and Sprockets Clean and Inspect .

### Installation Procedure

#### Tools Required

J 38612 Crankshaft Sprocket Installer

1. If removed install the camshaft thrust plate.

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.

2. Install the camshaft thrust plate bolts.

Tighten
Tighten the camshaft thrust plate bolts to 10 N·m (89 lb in).

3. Install the crankshaft sprocket using the J 38612 .
4. Remove the J 38612 .
5. Apply Engine Oil Supplement (EOS) GM P/N 1052367 or equivalent to the sprocket thrust surface.
6. Install the timing chain dampener to the block.

Tighten
Tighten the timing chain dampener bolts to 21 N·m (15 lb ft).

7. Install the timing chain onto the camshaft gear.
8. Hold the camshaft sprocket with the chain hanging down, and install the chain to the crankshaft gear.
9. Align the crankshaft timing mark (3) to the timing mark on the bottom of the timing chain dampener (2).
10. Align the timing mark on the camshaft gear, center line of the locator hole (6), with the timing mark on the top of the chain dampener (5).
11. Align the dowel in the camshaft with the dowel hole in the camshaft sprocket (1).
12. Install the camshaft sprocket bolt.
13. Draw the camshaft sprocket onto the camshaft using the mounting bolt.

Tighten
Tighten the camshaft sprocket bolt to 140 N·m (103 lb ft).

14. Coat the crankshaft and camshaft sprocket with engine oil.
15. Install the engine front cover. Refer to Engine Front Cover Replacement .