Inspection - Gear Tooth Patterns: Notes
WARNING: This page is about a different car, the 1991 Ford Aerostar. However, it is still accessible from the selected car via links, so may be relevant.
Wipe lubricant from internal parts. Rotate gears and inspect for wear or damage. Mount dial indicator to housing and check backlash at several points around ring gear. Backlash must be within specification at all points. If no defects are found, check gear tooth pattern contact.
NOTE:
Drive pattern should be well centered on ring gear teeth. Coast pattern should be centered, but may be slightly toward toe of ring gear teeth.