1935 Cadillac - GM Heritage Center

29
REAR AXLE
if the bearing is not replaced at the same time the
gear replacement is made.
It is also advisable to replace the cork and felt
gaskets for the front pinion bearing.
Complete instructions for replacing and adjusting
the rear axle gears are given below:
REMOVAL AND DISASSEMBLY
The replacement of the rear axle ring gear and
drive pinion necessarily requires the removal and
disassembly of the differential gear assembly. To
remove this unit, it is necessary first to remove the
propeller shaft and axle shafts. See Notes 2 and
3. Then the differential cover and reinforcement
plate are removed, after which the differential gear
assembly is dismounted or taken off of the differential
carrier. See Figs. 1 and 3, Plate 6.
The differential gear assembly is disassembled in
the following order.
1. Remove caps for differential side bearings
and take out adjuster rings.
2. Remove differential unit.
3. Remove ring gear from differential case or
gear mount on Cadillac cars. The ring gear is
riveted to the gear case on the LaSalle and both
parts must be replaced in case of wear or damage
to either one.
4. Remove drive pinion, front bearing retainer,
bearings and bearing spacer.
NOTE—Do not lose or damage the shims between
the front bearing retainer and the front end of
the differential carrier on the Cadillac.
5. Wash parts in gasoline or kerosine and dry
with air after which check all parts carefully.
The differential pinions and side gears may be
removed by removing the retaining screw in the
pinion shaft and driving out this shaft. It is not
necessary to remove these gears, however, for
replacing the ring gear and drive pinion on the
Cadillac.
Examine the bearings, the bearing mounts and
the differential gears. They should he smooth,
free from pits and the gears and bearings should
not be chipped or broken.
The flange of the Cadillac differential case
should also be checked for wobble and eccentricity;
it should run true laterally and radially
within .001 in. or .004 in. when tested on the back
of the ring gear. A convenient way to making
this test is to install the differential case and
bearings in position in the carrier and check the
flange with a dial indicator clamped to the carrier
or bearing cap studs using holder HM91220.
The hubs of the differential side gears should
have no more than .005 in. radial clearance in the
differential case. End-play in these gears should
not exceed .020 in.
The two differential pinion gears should have a
clearance of not more than .010 in. on the pinion
shaft and not more than .020 in. backlash with the
side gears.
REASSEMBLY AND INSTALLATION
Reassembly of the differential gear assembly is
accomplished in the following order:
1. Install bearings and bearing spacer on the
drive pinion shaft.
2. Install drive pinion and bearings in differential
carrier, being sure to install the spacing
shims between the front bearing retainer and the
front end of the differential carrier on the Cadillac.
Next install the universal joint flange and make
an initial adjustment on the drive pinion as
explained in section "Adjustment of Drive
Pinion." Tighten flange retaining nut on the
front end of the drive pinion shaft and lock it in
position.
NOTE—Lubricate the drive pinion bearings when
installing them to insure initial lubrication.
3. Install differential side gears and pinions
(provided these gears are removed).
4. Install ring gear on differential case on
Cadillac cars. Tighten retaining screws securely
using an 18-inch wrench and lock with wire.
Wire two screws together, installing the wire in
such a way that tension of the wire on the screws
will tend to tighten the screws rather than loosen
them. The ring gear for LaSalle cars is supplied
riveted to the gear case.
5. Install differential unit in position in differential
carrier, after which install the adjuster rings
and the bearing caps.
6. Make initial adjustment of gear mesh. See
section "Adjustment of Ring Gear."
7. Install the axle shafts (See Note 2), lubricating
the felt washers in the wheel.
8. Install rear axle under car.
9. Adjust gear mesh as explained under "Testing
Ring Gear for Proper Tooth Contact."
10. Install reinforcement plate, differential cover
and fill differential to proper level with recommended
transmission and rear axle lubricant.
Adjustment of Gear Mesh
In the design of the rear axle provision is made
for adjusting the drive pinion and ring gear so
that the teeth may be meshed correctly, and for
locking all adjustments securely. Ordinarily old
gears that have been running noisy for some time
cannot be adjusted satisfactorily to eliminate the
noise. In such cases it is necessary to replace the
gears with new ones.