Ford Workshop Service and Repair Manuals

NOTE:Valve guides tend to wear in an hourglass pattern. The ball gauge can be inserted into the combustion chamber side of the valve guide if necessary. Use a ball gauge to determine the inner diameter of the valve guides in 2 directions at the top, middle and bottom of the valve guide.

Measure the ball gauge with a micrometer. Refer to the appropriate section in Group 303 for the specification.

If the valve guide is not within specifications, ream the valve guide and install a valve with an oversize stem or remove the valve guide and install a new valve guide.