ARB RD12 - Manual (Page 11)

3 Bench Measurement
9
3.1 Measurement for Pre-Load Shimming
When fitting an ARB Air Locker, a replacement bearing and variable
shim pack (supplied) are used on the right hand side (opposite the ring
gear) in order to achieve the correct ring and pinion backlash and
carrier bearing pre-load once the Air Locker has been installed.
Because of this, the original shims and bearing from this side will not
be reused.
The original bearing type and shim type are used on the left hand (ring
gear) side of the Air Locker, however, in order to reproduce a similar
backlash and pre-load to that of your existing differential,
measurements need to be taken so that the correct shim thickness
can be determined for this side.
c Secure the differential to a work bench.
c Remove the bolts that hold the ring gear in place.
c Using a plastic or copper hammer, tap in a circle around the ring
gear to separate it from the differential carrier.
c Remove the original bearings and shims from the differential carrier
using a bearing puller.
NOTE : Keep the shims separated so that they can be
identified as to which end of the differential they came
from.
c Using a caliper or similarly accurate measurement method
(i.e., able to take accurate measurements within 0.04mm [0.0015”]),
measure the distance from the bearing shoulder to the ring gear
mounting face (shown as ‘A’ in Figure 4.) and record this
measurement as ‘A’.
c Measure the thickness of the shim pack removed from the ring gear
side of the differential carrier (shown as ‘B’ in Figure 4.).and record
this measurement as ‘B’.
c Measure the distance from the Air Locker bearing shoulder to the
ring gear mounting face (shown as ‘C’ in Figure 5.) and record this
measurement as ‘C’.