ARB RD75 - Manual (Page 9)

2 Removing the Existing Differential
7
2.5 Checking the Current Backlash Amount
IMPORTANT:
This step is a precautionary measure recommended by ARB
due to the fact that some after market ring and pinion sets
have been manufactured to run with different backlash
settings than those specified by your vehicle manufacturer.
Although ARB must recommend you set backlash according
to your service manual guidelines, we also advise that you
compare the backlash measurements taken here to the
recommended backlash settings in your vehicle service
manual. Measurements found to be outside of your service
manual recommendations may indicate the need to deviate
from those settings in order to achieve quiet running with a
good contact mark.
Refer to your vehicle service manual or your local authorized
ARB installer for more information.
Set a dial indicator on one of the ring gear teeth. (Fig.2.)
Figure 2.
While supporting the pinion gear by holding the pinion flange, 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.
Rotate the differential center 90
° and measure again for accuracy.
Record the average of all measurements.