Envoy 4WD V8-5.3L VIN M (2005)
6. Remove the crankshaft sprocket.
7. Remove the crankshaft sprocket key, if required.
8. Clean and inspect the timing chain and sprockets.
Installation Procedure
1. Install the key into the crankshaft keyway, if previously removed.
2. Tap the key (1) into the keyway until both ends of the key bottom onto the crankshaft.