Differential Assembly: Testing and Inspection

Carry out a tooth contact pattern check in conjunction with the final drive overhaul procedure. Sparingly paint eight or ten of the drive gear teeth with a stiff mixture of engineers blue. Move the painted gear teeth in mesh with the pinion until a good impression of the total contact is obtained.

The result should conform with the ideal tooth contact pattern (Fig 1).

KEY TO FIGS 1-5

A The HEEL is the larger outer end of the tooth.
B The TOE is the small or inner end of the tooth.
C The DRIVE side of the drive gear tooth is convex.
D The COAST side of the drive gear tooth is concave.

Fig.1:

Fig 1 - Ideal tooth contact pattern.

Fig.2:

Fig 2 - High tooth contact pattern.

Fig.3:

Fig 3 - Low tooth contact pattern.

Fig.4:

Fig 4 - Toe contact pattern.

Fig.5:

Fig 5 - Heel contact pattern.