Contact Pattern Location

WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

In general, desirable ring gear tooth patterns must have the following characteristics:

Drive pattern on the drive side ring gear well centered on the tooth.
Coast pattern on the coast side ring gear well centered on the tooth.
Clearance between the pattern and the top of the tooth.
No hard lines where the pressure is high.

Fig 1: Checking Gear Tooth Contact Pattern
Courtesy of FORD MOTOR CO.

Acceptable ring gear tooth patterns for all axles.

Fig 2: Positioning Correct Backlash With Thinner Pinion Shim
Courtesy of FORD MOTOR CO.

Correct backlash with a thinner pinion position shim required.

Fig 3: Positioning Correct Backlash With Thicker Pinion Shim
Courtesy of FORD MOTOR CO.

Correct backlash with a thicker pinion position shim required.

Fig 4: Identifying Differential Ring Gear Tooth Patterns (Correct Pinion Position Shim That Requires Decrease In Backlash)
Courtesy of FORD MOTOR CO.

Correct pinion position shim that requires a decrease in backlash.

Fig 5: Identifying Differential Ring Gear Tooth Patterns (Correct Pinion Position Shim That Requires An Increase In Backlash)
Courtesy of FORD MOTOR CO.

Correct pinion position shim that requires an increase in backlash.