Important: 

1. Remove the camshaft housing cover to the camshaft housing retaining bolts.

Important: Use the reverse of the tightening procedure when loosening the camshaft housing to the cylinder head retaining bolts. Leave the bolts loosely in place to hold the camshaft housing while separating the camshaft cover from the housing.

2. Remove the camshaft housing to the cylinder head retaining bolts.
3. Remove the camshaft sensor bolt.
4. Remove the camshaft sensor.

Important: Push the cover off of the housing. Remove it by threading four of the housing to head retaining bolts into the tapped holes in the camshaft housing cover.

Tighten the bolts evenly in order to prevent the cover from binding on the dowel pins.
5. Remove the two loosely installed camshaft housing to head bolts.
6. Remove the camshaft housing cover. Discard the seals.
7. Loosely reinstall one camshaft housing to the cylinder head bolt in order to retain the housing during camshaft and lifter removal.
8. Remove the camshaft. Be careful not to damage the camshaft or journals.




Important: Keep the valve lifters in order so they can be installed in the same location.

9. Remove the valve lifters.
10. Use the following steps to minimize lifter bleed down:

•	Store the lifters upside down on a level surface. Keep the camshaft contact surface down.

•	The lifters can also be submerged in clean engine oil.

11. Replace the lifters if they are faulty. These lifters are not repairable.
12. Coat the lifter with Camshaft and Lifter Prelube GM P/N 12345501 or equivalent. Do not get the prelube on the camshaft cover seals because they could swell.
13. Add Engine Oil Supplement GM P/N 1052367 or equivalent to the engine oil.
14. Remove the camshaft housing.
15. Remove the camshaft housing gasket.