ARB RD90 - Manual (Page 20)

3 Installing the Air Locker
18
NOTE : The preload gap should be the same when measured
all the way around the housing. If this is not true, then
reposition the shallow clamshell half and re-measure.
c Subtract the amount measured at the preload gap from the
thickness of the shim pack placed on top of the bearing cup.
c Record the result as this is your true ‘end float’ amount.
3.6 A B Calculation & Selection of Preload Shims
c Consult your vehicle manufacturer’s service manual to determine
the carrier bearing preload amount specified for your vehicle.
NOTE : If your service manual specifies preload in terms of a
torque value measured off the drive pinion flange,
then assume a preload amount of 0.25mm [0.01”] for
the following calculations. Once you have assembled
the housing to check the final backlash (Refer to
Section 3.12 Checking the Backlash) you should verify
that your preload is correct using a torque wrench and
your service manual’s table of values.
c Add the specified preload amount to the end float measurement
determined with the feeler gauge to determine a shim amount for
‘E’ (Refer to Figure 9.).
PRELOAD + END FLOAT = SHIM PACK
c Create a shim pack ‘E’ to closely match the measured amount.
NOTE : When creating the shim pack ‘E’, use at least 0.75mm
[0.030”] of the Air Locker shim pack between the
factory shim and the bearing cup in order to prevent
the cage of the bearing from contacting the factory
shim.
To achieve this desired shim thickness you can:
•
Machine down the factory shim thickness.
•
Add shims between the factory shim and the bearing cup.
•
Purchase new factory shims at the desired thickness.
•
Use a universal shim kit available from most drive train specialists.
NOTE : Do not add shims between the bearing cone and the
bearing seat and NEVER machine the Air Locker.