Important:
• | Read the entire procedure before removing the camshaft housing. |
• | The camshaft housing to the cylinder head gasket must be replaced
any time the camshaft housing to the cylinder head bolts are loosened or removed. |
• | During disassembly, be sure that the valve lifters are kept together
and identified in order so that the valve lifters may be reinstalled in their
original locations. |
- Remove the exhaust camshaft rear cover.
- Remove the exhaust camshaft rear cover gasket.
Important: Use the reverse of the tightening procedure when loosening the camshaft
housing to the cylinder head retaining bolts.
- Remove the exhaust camshaft housing to the cylinder head bolts.
Important: Leave 2 bolts loosely in place to hold the camshaft housing while separating
the camshaft cover from the housing.
- Push the cover off the camshaft housing by threading four of the housing
to the head retaining bolts into the tapped holes in the camshaft cover.
Important: Tighten the bolts evenly to prevent the cover from binding on the dowel
pins.
- Remove the two loosely installed camshaft housing to the head bolts.
- Remove the camshaft cover. Discard the seals.
- Loosely install one camshaft housing to the cylinder head bolt
to retain the housing during the camshaft and lifter removal.
- Remove the camshaft. Be careful not to damage the camshaft or
journals.
- Remove the valve lifters. Keep the valve lifters in order so that
the valve lifters may be reinstalled in the same location from which they
were removed.
- Do one of the following to minimize lifter bleed down:
• | Store the lifters upside down on a level surface. Keep the camshaft
contact surface down. |
• | Store the lifters submerged in clean engine oil. |
Important:
• | The valve lifters are not repairable. Replace the lifters if the
lifters are faulty. Do not get prelube on the camshaft cover seals because
the seals will swell. |
• | Coat the lifter with Camshaft and Lifter Prelube GM P/N United
States 12345501, GM P/N Canada 992704 or an equivalent
before installation. |
- If new lifters are installed, add Engine Oil Supplement GM P/N United
States 1052367, GM P/N Canada 992869 or an equivalent
to the engine oil.
- Remove the camshaft housing.
- Remove the camshaft housing gasket.