Duramax LLY – TIMING CHAIN-SPROCKET-GEAR INSTALLATION

1. Rotate crankshaft so #1 piston is at TDC.

2. Install sprocket drive keys in camshaft and crankshaft (Figure 2-167).

3. Place block in upright position so cam is facing up. Then rotate camshaft so drive key is toward top of block.

4. Assemble timing chain and sprockets. Make sure sprocket timing marks are aligned as shown (Figure 2-167).

5. Align sprockets with drive keys in crankshaft and camshaft. Then install chain and sprockets as assembly (Figure 2-167). Turn camshaft to align sprockets if necessary. Do not turn sprockets.

6. Check chain deflection with dial indicator. If deflection is greater than 0.51 in. (13 mm), chain is stretched and will have to be replaced.

7. Install injection pump drive gear, thrust washer, flat washer (if equipped), and bolt (Figure 2-167). Tighten bolt to 126 lb-ft (171 Nโ€ขm) torque. Apply 1-2 drops Loctite 242 to bolt threads before installation. Position gear so timing marks is at 12 oโ€™clock position.

8. Lubricate chain, sprockets, and gear with engine oil.