ARB RD137 - Manual (Page 9)

2 Removing the Existing Differential
7
c Set a depth indicator on one of the ring gear teeth as in Figure 2.
Figure 2.
c While supporting the pinion gear by holding the drive shaft, rotate
the differential in both directions while observing the maximum
variation in depth from the indicator (i.e., the highest value minus
the lowest value). This value is referred to as the ring and pinion
backlash.
c Rotate the differential center 90
°
and measure again for accuracy.
c Record the average of all measurements.