ARB RD12 - Manual (Page 25)

4 Installing the Air Locker
23
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.
Figure 15.
c Refer to your vehicle service manual for the specified maximum
and minimum amounts of backlash. If the backlash is not within the
specifications then the differential will have to be removed and re-
shimmed.
4.9.1 Re-Shimming the Backlash
NOTE : This step is only necessary when adjusting for
incorrect backlash.
c Reapply the spreader to the differential housing.
c Remove the bearing caps.
c Remove the differential.
c To increase the amount of backlash, reduce the shim thickness ‘D’
(Fig.5.) and increase the shim thickness ‘E’ (Fig.8.) by the same
amount. Reverse this step to decrease the backlash.
c Remount the differential as before.
c Release spreader tension.
c Check backlash again as before.