Valve Guide: Service and Repair
DESCRIPTIONIf the valve stem-to-valve guide clearance exceeds the service clearance, replace the valve guide and ream the valve guide to the standard diameter of 7.02-7.04 mm (0.276-0.277 inch). Always reface the valve seat after the valve guide has been replaced.
REPLACEMENT
1. Press out original guide and install service bushing.
NOTE: If it becomes necessary to ream a valve guide to install a valve with an oversize stem, a hand-reaming kit is available which contains the following reamer and pilot combinations:
A 0.38 mm (0.015 inch) OS reamer with a 0.76 mm (0.030 inch) OS pilot.
A 0.76 mm (0.030 inch) OS reamer with a 0.38 mm (0.015 inch) OS pilot.
2. Hand ream the valve guide.
3. Use a suitable scraper to break the sharp corner (ID) at the top of the valve guide. Failure to do so may result in possible valve train wear and/or damage.
4. Reface valve seat as required. Install standard-size valve stem seal.
5. Check valve lash (collapsed tappet gap).