Valve Guide Reaming

3.0L (2V) Engine

CAUTION: Always reface the valve seat after the valve guide has been replaced, and use a suitable scraper to break the sharp corner (inside diameter) at the top of the valve guide. Failure to do so may result in possible valve train wear and/or damage.

If it becomes necessary to ream a valve guide to install a valve with an oversize stem, a reaming kit is available which contains the following reamer and pilot combinations: 0.38 mm (0.015 inch) "OS" reamer with 0.076 mm (0.003 inch) "OS" pilot, and a 0.76 mm (0.030 inch) reamer with a 0.38 mm (0.015 inch) "OS" pilot.





When replacing a standard size valve with an oversize valve, always use the reamer in sequence (smallest oversize first then next smallest, and so forth) so the reamers will not be overloaded.

NOTE: If oversize valve stems and oversize stem seals are not available, bore out original guide and install service bushing. Ream ID for specified clearance for standard-size valve. Reface valve seat, as required. Install standard-size valve stem seal.

CAUTION: The interference angle of the valve and seat should not be lapped out. Remove all grooves or score marks from the end of the valve stem and chamfer it as necessary. Do not remove more than 0.25 mm (0.010 inch) from the end of the valve stem or excessive valve clearance may occur.

If the valve face runout is excessive and/or the pits and grooves must be removed, reface the valve to a true 45-degree angle. Remove only enough stock to correct the runout or to clean up the pits and grooves.
If the edge of the valve head is less than 0.79 mm (1/32 inch) thick after grinding, replace the valve because the valve will run too hot in the engine.
If the valve and/or valve seat has been refaced, check the clearance between the rocker arm pad and the valve stem with the valve train assembly installed in the engine.