GM 12625439
Camshaft

The radiator support must be removed first and then the valve lifters before starting the Camshaft replacement process. The next sequence includes eliminating the Timing Chain along with the Camshaft position actuator and the solenoid valve. First remove the Camshaft retainer bolts (204) and retainer (203) while paying attention to the Camshaft bearings because all Camshaft journals share the same diameter. Fix a bolt to the Camshaft for handling purposes before removing it from the engine block by rotating it gently. Thoroughly inspect the Camshaft together with its bearings while performing cleaning operations. A new Camshaft will require valve lifter replacement at the same time. Insert clean engine oil on all Camshaft journal bearings before beginning to reinstall the Camshaft through the engine block with the bolt as a guide. At the front of the Camshaft bolt must be removed while ensuring that the retainer has the sealing gasket facing the engine block along with a clean gasket surface. Use the Camshaft retainer part number 203 along with bolts 204 while securing the hardware using 25 nm (18 lb ft) of torque on first design hex head bolts and 15 nm (11 lb ft) on the second design torx(R) head bolts. The process should begin with reinstalling the Timing Chain then the Camshaft position actuator alongside solenoid valve followed by valve lifters and ending with the radiator support.

With the sealing gasket facing the engine block, keeping the gasket surface clean.