70. Camshaft Installation
Important: Replace the valve lifters when a new camshaft is installed.
1. Install the camshaft sprocket key.
2. Install the camshaft sprocket spacer, with the ID chamfer facing the camshaft.
3. Install the camshaft.
3.1. Coat the camshaft lobes with Lubricant GM P/N 1052367, or the equivalent.
3.2. Lubricate the camshaft bearing journals with engine oil.
3.3. Carefully insert the camshaft into the block, in order to avoid damage to the camshaft bearings.
4. Install the thrust bearing.
Notice: Refer to Fastener Notice in Service Precautions.
5. Install the thrust bearing bolts.
^ Tighten the bolts to 25 Nm (17 ft. lbs.).
Valve Lifter Installation
Notice: Prime the new valve lifters before installation. The valve lifters may be damaged if the valve lifters are dry when the engine is started.
Important: Replace the lifters when you install a new camshaft. Some engines will have both standard and 0.25 mm (0.010 inch) oversize valve lifters. The oversize lifter will have the number 10 etched on the side. The block will be stamped OS on the cast pad adjacent to the lifter bore and on the top rail of the cylinder case above the lifter bore.
1. Install the valve lifters to the engine.
^ Prime the new valve lifters before installation, by working the lifter plunger while submerged in clean kerosene or diesel fuel.
^ Coat the lifter roller and the bearings with lubricant GM P/N 1052367, or equivalent.
^ Install the lifters in their original location.
Important: Ensure that the straight edge of the guide plates and the clamps face away from the cylinders.
2. Install the guide plates.
Notice: Refer to Fastener Notice in Service Precautions.
3. Install the clamps.
^ Tighten the clamp bolts to 27 Nm (20 ft. lbs.).
Important: If the engine will not turn over by hand, one or more of the lifters may be binding in the guide plates.
4. After installing the clamps, turn the crankshaft by hand 720° (two full turns), in order to ensure the free-movement of the lifters in the guide plates.