Replacing Valve Guide
Replace valve guide if clearance exceeds specification. Valve guides are either pressed, hammered or shrunk in place, depending upon cylinder head design and type of metal used.
Remove valve guide from cylinder head by pressing or tapping on a stepped drift. See Fig 1. Once valve guide is installed, distance from cylinder head to top of valve guide must be checked. This distance must be within specification.
Aluminum heads are often heated before installing valve guide. Valve guide is sometimes cooled in dry ice prior to installation. Combination of a heated cylinder head and cooled valve guide ensures a tight guide fit upon assembly. The new guide must be reamed to specification.