REMOVAL & INSTALLATION
See Figures 1 through 5
If excessive camshaft wear is found, or if the engine is completely rebuilt, the camshaft bearings should be replaced.
The front and rear bearings should be removed last, and installed first. Those bearings act as guides for the other bearings and pilot.
- Drive the camshaft rear plug from the block.
- Assemble the removal puller with its shoulder on the bearing to be removed. Gradually tighten the puller nut until the bearing is removed.
- Remove the remaining bearings, leaving the front and rear for last. To remove these, reverse the position of the puller, so as to pull the bearings towards the center of the block. Leave the tool in this position, pilot the new front and rear bearings on the installer, and pull them into position.
- Return the puller to its original position and pull the remaining bearings into position.
You must make sure that the oil holes of the bearings and block align when installing the bearings. If they don't align, the camshaft will not get proper lubrication and may seize or at least be seriously damaged. To check for correct oil hole alignment, use a piece of brass rod with a 90° bend in the end as shown in the illustration. Check all oil hole openings. The wire must enter each hole, or the hole is not properly aligned.
- Replace the camshaft rear plug, and stake it into position. On the diesel, coat the outer diameter of the new plug with GM sealant #1052080 or equivalent, and install it flush to 1 / 32 in. (0.794mm) deep.