Contact Pattern Location

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.

Acceptable ring gear tooth patterns for all axles.

Fig 1: Identifying Acceptable Ring Gear Tooth Patterns

Courtesy of FORD MOTOR CO.

Correct backlash with a thinner pinion position shim required.

Fig 2: Identifying Wear Pattern Requiring Thinner Pinion Position Shim

Courtesy of FORD MOTOR CO.

Correct backlash with a thicker pinion position shim required.

Fig 3: Identifying Wear Pattern Requiring Thicker Pinion Position Shim

Courtesy of FORD MOTOR CO.

Correct pinion position shim that requires a decrease in backlash.

Fig 4: Identifying Wear Pattern Requiring Decrease In Backlash

Courtesy of FORD MOTOR CO.

Correct pinion position shim that requires an increase in backlash.

Fig 5: Identifying Wear Pattern Requiring Increase In Backlash

Courtesy of FORD MOTOR CO.