3. Backlash – The distance between the mating surfaces of the ring and pinion gears.
Adjusted by moving the ring gear inward or outward from the pinion gear by
shimming the carrier.
4. Carrier bearing preload – The preload applied to the carrier bearings when installed in
the axle housing.
1. Setup Without Pinion Depth Setting Tool
In order to obtain the correct set up without a pinion depth setting tool, the following
procedure is suggested:
a. Unless otherwise instructed, start with the original pinion depth shim. On most
rear ends this will require a bearing puller such as (G2 80-BRGPLLR) to remove
the old pinion bearing from the original pinion.
b. Press the new bearing on the new pinion shaft using the original shim.
c. After replacing the pinion races, install the new pinion into the housing without a
crush collar/preload shims and without the pinion seal.
d. Use the old pinion nut to secure the yoke and tighten to obtain the factory
e. Tap on the yoke a few times to ensure that the races are fully seated and recheck
your pinion preload tighten the nut to reset the preload to factory specs.
f. Install the carrier to fit snugly in the housing and set the backlash to
approximately .008” to .010” by changing the carrier shims (or adjusters) on each
side as required.
g. You can now check the tooth pattern by using marking compound on the ring gear
teeth. Add or subtract pinion depth shims in increments of .003” to obtain a new
h. Adjust carrier shims to obtain the proper backlash specified for your application
when making pinion depth changes.
i. Refer to the desired pattern as indicated in the Tooth Contact Pattern chart.
j. After the proper pattern has been established, you can remove the carrier, remove
the pinion, and install the crush sleeve and or preload shim stack along with a new
pinion seal and nut. (use thread locker on the nut)Set pinion preload to factory
k. Reinstall the carrier assembly and recheck the backlash, pattern, and carrier
preload. Torque main caps to factory specs.
2. Setup With Pinion Depth Setting Tool
a. Start by installing the pinion in the housing as per the pinion depth dimensions.
This depth is obtained by using pinion shims behind the inner pinion bearing or
behind the inner pinion race or between the pinion support and the case (Ford 9”
and GM 10.5”)
b. See figure 1. The thickness of the pinion shims is determined by using a pinion
depth setting tool measure the checking distance. Obtaining the correct pinion
depth is very critical.