Ford 2003 Mustang Workshop Manual page 112

5. In the following steps, the movement of the contact pattern along the length is indicated as
toward the" heel" or "toe" of the differential ring gear.
Item Description
1 Heel
2 Toe
6. Apply a marking compound to a third of the gear teeth on the differential ring gear. Rotate the
differential ring gear several complete turns in both directions until a good, clear tooth pattern is
obtained. Inspect the contact patterns on the ring gear teeth.
7. A good contact pattern should be centered on the tooth. It can also be slightly toward the toe.
There should always be some clearance between the contact pattern and the top of the tooth.
Tooth contact pattern shown on the drive side of the gear teeth.
8. A high, thick contact pattern that is worn more toward the toe.