Contact Pattern Location

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

• Drive pattern on the drive side differential ring gear well centered on the tooth.
• Coast pattern on the coast side differential 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 differential ring gear tooth patterns for all axles.

Fig 1: Identifying Acceptable Ring Gear Tooth Pattern

Courtesy of FORD MOTOR CO.

Correct backlash with a thinner pinion position shim as necessary.

Fig 2: Identifying Ring Gear Tooth Patterns - Correct Backlash With Thinner Pinion Position Shim

Courtesy of FORD MOTOR CO.

Correct backlash with a thicker pinion position shim as necessary.

Fig 3: Identifying Ring Gear Tooth Patterns - Correct Backlash With Thicker Pinion Position Shim

Courtesy of FORD MOTOR CO.

Correct pinion position shim that requires a decrease in backlash.

Fig 4: Identifying Ring Gear Tooth Patterns - Decrease Backlash

Courtesy of FORD MOTOR CO.

Correct pinion position shim that requires an increase in backlash.

Fig 5: Identifying Ring Gear Tooth Patterns - Increase Backlash

Courtesy of FORD MOTOR CO.