c. Remove the differential and ring gear assembly from
(11) Install the drive pinion and bearing assembly in
d. Remove the differential bearing cones. Install the cor-
(12) Install the original front bearing shim pack fol-
rect thickness shim pack as determined in step 2, between the
lowed by the front bearing cone.
bearing cone and the differential case hub shoulder, using
(13) Install the companion flange and nut. Tighten
tool C4028-A. Add an additional 0.015-inch shim to the
the nut to 220-220 ft-lbs.
drive gear tooth side of the differential and install the dif-
(14) To check torque, rotate the pinion shaft with an
ferential bearing cones. This additional 0.015-inch shim
inch-pound torque wrench. The drive pinion must be verti-
pack provides the correct bearing preload and backlash.
cal for this check. The torque reading to start the shaft
e. Position spreader tool W-l29-A in the locating holes
turning will be disregarded. The torque reading while ro-
of the carrier and tighten the screw finger-tight. Install the
tating the shaft should be 20-40 in-lbs with new bearings
dial indicator and spread the carrier 0.015 to 0.020 inch. Do
or 10-20 in-lbs if the old bearings were used.
not exceed this limit so that the differential and ring gear
(15) Add or remove shims from behind the front
assembly can be placed in the carrier.
bearing cone to obtain the correct (bearing preload) turning
f. Install the bearing caps in their respective positions as
torque. Shims are available in the following thicknesses:
indicated by identification marks on the caps and the car-
0.003,0.005,0.010, and 0.030 inch.
rier. Remove the spreader tool. Coat the bearing cap bolt
(16) After the correct bearing preload has been
threads with sealing compound and install and tighten the
established, pinion setting depth should be rechecked.
(17) Remove the companion flange and nut.
g. Tap the drive gear lightly with a rawhide hammer to
properly seat the differential bearing and cups. Care must
(18) Install the oil slinger and gasket. Install a new
be taken in this operation to prevent nicking the teeth of
oil seal. If the dust shield has been removed, install a new
the ring gear or drive pinion as they are meshed together.
Tighten the bearing cap bolts to 70-90 ft-lbs.
(19) Install the companion flange, washer, and nut.
h. Attach a dial indicator to the carrier and with the indi-
Tighten the nut to 200-220 ft-lbs, holding the flange with
cator contact point contacting the ring gear tooth (figure
measure the backlash between
the ring gear and
(20) Turn the carrier and tube assembly in the hold-
ing fixture with the cover side facing upward. Install the
axle shaft inner oil seals.
20-3. Differential Bearing Preload and Drive Gear
and Pinion Backlash.
the drive pinion and bearings installed and
bearing preload set, install the differential case and ring gear
assembly with their respective bearing cups. Install the bear-
ing caps in their positions, aline identification marks, and
tighten the cap bolts finger-tight. Refer to the measurement
the drive pinion was installed, represents the total clearance
between the differential bearing cups and the carrier casting.
Perform the following steps to determine the thickness of
shims required behind each bearing cone to take up the
clearance and establish the correct bearing preload and back-
b. Install a dial indicator and position the contact point
against the back face of the ring gear. Move the differential
Figure 20-18. Checking Backlash Between
and ring gear assembly tight against the drive pinion. Set the
Drive Gear and Pinion.
dial indicator on "0." Move the differential and ring gear
assembly in the opposite direction as far away from the
pinion as possible, and note the reading on the dial indicator,
This reading represents the thickness of shim pack necessary
to take up the clearance between the bearing cup and the
case on the ring gear side of the differential assembly, Sub-
tract this reading from the previously recorded total reading
to obtain the amount of shims necessary to take up the
clearance between the bearing cup and the case at the pinion
side of the differential.