ARB RD90 - Manual (Page 30)

3 Installing the Air Locker
28
c To decrease the amount of backlash, reduce the shim thickness ‘D’
(Fig.7.) and increase the shim thickness ‘E’ (Fig.9.) by the same
amount. Reverse this step to increase the backlash.
c Remount the differential as before.
c Check backlash again as before.
3.12.3 B Backlash for Clamshell Housing
c Set a long series lever type dial indicator on one of the ring gear
teeth. Access to the ring gear teeth is gained through the oil filler
hole. (Refer to Figure 21.)
Figure 21.
c Insert a large flat screwdriver or pry-bar through one of the axle
stub holes so that it wedges between the cross shaft and the carrier
body so that the differential center can be rotated by the cross shaft
(not by the spline of one of the differential gears.
c While supporting the pinion gear by holding the drive shaft flange,
rotate the differential in both directions (with the screwdriver or pry-
bar) 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.