Ford Ranger Maintaince And Repair Manual page 472

HOW TO USE THIS BOOK
Check the valve spring for squareness on a flat surface; a carpenter's square can be used
Cylinder Head
There are several things to check on the cylinder head: valve guides, seats, cylinder head surface flatness,
cracks and physical damage.
VALVE GUIDES
Now that you know the valves are good, you can use them to check the guides, although a new valve, if
available, is preferred. Before you measure anything, look at the guides carefully and inspect them for any
cracks, chips or breakage. Also if the guide is a removable style (as in most aluminum heads), check them for
any looseness or evidence of movement. All of the guides should appear to be at the same height from the
spring seat. If any seem lower (or higher) from another, the guide has moved. Mount a dial indicator onto the
spring side of the cylinder head. Lightly oil the valve stem and insert it into the cylinder head. Position the
dial indicator against the valve stem near the tip and zero the gauge. Grasp the valve stem and wiggle towards
and away from the dial indicator and observe the readings. Mount the dial indicator 90 degrees from the initial
point and zero the gauge and again take a reading. Compare the two readings for an out of round condition.
Check the readings against the specifications given. An Inside Diameter (I.D.) gauge designed for valve
guides will give you an accurate valve guide bore measurement. If the I.D. gauge is used, compare the
readings with the specifications given. Any guides that fail these inspections should be replaced or machined.
466 INSPECTION