Valve Clearance: Adjustments

Valve Clearance Adjustment (12.29.48)





1. Remove the left-hand valve cover.
2. Remove the right-hand valve cover.
3. Use a cloth to wipe away as much oil as possible from the tappet and shim.

4. CAUTION: Rotating the crankshaft in a counterclockwise direction may cause engine damage. Crankshaft journals are directionally machined. Rotating the crankshaft counterclockwise can raise burrs on bearing surfaces, reducing engine life.

CAUTION: Camshaft lobes must be 180 degrees away from each valve tappet or the valve clearance will be incorrect.

Rotate the engine clockwise to position the camshaft lobe away from the shim surface.

5. Install the base plate of the valve clearance adjusting tool to the relevant cylinder head using the bolts supplied.
^ Secure the tool to the valve cover retaining holes.





6. CAUTION: Do not rotate the crankshaft while the attachment is installed to the base plate.

Install the attachment of the tool to the base plate to remove the relevant shims.

1. Adjust the fingers of the attachment to the highest position.
2. Install the attachment to the base plate.
3. Tighten the retaining screws to secure the attachment to the base plate.





7. NOTE: Use a mirror to help locating the fingers of the special tool as access is restricted.

Position the fingers on the outer edges of the tappet. Make sure the recessed step on each finger locates on the edge of the tappet.





8. Tighten the special tool to compress the valve springs.





9. WARNING: The following operations require the use of compressed air. Always wear suitable eye protection.

CAUTION: Do not use a magnet to remove shims. Failure to follow these instructions may result in damage to the vehicle.

Remove, clean and measure the shim.

1. Surround the immediate working area with a cloth to retain any loose shims displaced by the compressed air.
2. Use special tool aimed at the edge of the shim to lift it from the tappet. Remove the shim from each tappet, noting the position of each one.





10. NOTE: Two shims within each procedure are possible to be replaced using the special tool.

Use the following formula to calculate the required shim thickness.

^ Original shim thickness + measured shim clearance - desired clearance = required shim thickness.

11. CAUTION: Do not use a magnet to install shims. Failure to follow these instructions may result in damage to the vehicle

NOTE: Shims must be fitted with the size markings facing the tappet, not the camshaft.

Apply a light coat of engine oil to the replacement shim(s) and install.

12. Loosen the special tool to allow the valve springs to return to their normal position.





13. Using the feeler gauge set, measure the clearance between the camshaft and the shim surface. Record and check the readings.
14. When the valve clearance is correct, remove the attachment from the base plate and repeat the procedure for the following two valves to be adjusted.
15. Install the right-hand valve cover.
16. Install the left-hand valve cover.