2. Dry the shaft with compressed air.
3. Check the condition of the shaft journals (1), look for signs of scoring or excessive wear.
4. Check the condition of the camshaft cams (2), look for signs of scoring or excessive wear.
5. On LY6/L76/L92 engines, check the cleanliness of the oil supply channels (3) to the variable valve timing system drive
6. Check the condition of the thread (4) for the sprocket mounting bolt or the variable valve timing system clutch mounting valve.
7. Check the condition of the camshaft sprocket dowel pin (204).
8. Check the condition of the camshaft axial locking pin, look for signs of wear or damage to the sealing gasket.
If the axle retainer seal is not damaged, it can be used again.
9. Check the reliability of the fit of the camshaft bearing shells in the cylinder block.
10. Inspect the camshaft bearings for signs of excessive wear or scoring, replace the bearings if necessary.
11. Measure the diameter of the camshaft journals to determine the degree of wear and loss of geometry.
- If the ovality of the shaft journals is more than 0.025 mm, replace the camshaft.
- If the journal diameter is less than 54.99 mm, replace the camshaft.
12. Measure the height of the camshaft lobes and compare with the specification data.
13. Measure the deflection of the camshaft at the center journal.
- a) Install the camshaft in supports with V-shaped notches or in a machine with centers.
- b) Measure the runout of the center journal. If the deflection of the camshaft exceeds 0.05 mm, replace the camshaft.
14. Measuring cam lift.
Caution: Measuring cam lift is used to determine the degree of cam wear BEFORE disassembling the engine.
- a) Remove the valve drive rocker arms.
- b) Turn the crankshaft until the push rod is lowered to its maximum position. Install a dial indicator on the cylinder head.
- c) Place the indicator leg on the end of the pusher. Set the indicator to zero.
- d) Slowly rotate the crankshaft clockwise and read the maximum indicator reading.
- d) Compare the obtained cam lift with the given specifications.
[The original text can be found on the website «ChevyMan»]