Buick LeSabre 1965 Service Manual page 388

6-22
REAR AXLE, 46, 48, 49000 SERIES
PINION FLANGE
-HUB BOLT
•AXLE SHAFT
-RETAINER (OUTER)
PINION AXLE
RETAINING BOLT
PINION
AXLE
PINION NUT
WASHER
SLINGER
OIL SEAL
FRONT PINION BEARING
COLLAPSABLE SPACER
REAR PINION BEARING
DRIVE PINION
FILLER PLUG
BEARING
V - O I L SEAL
RETAINER (INNER)
GASKET
BRAKE BACKING PLATE
SHIM
SIDE BEARING
WASHER
RING GEAR
COVER
A seal in the front of the carrier
bears against the pinion flange to
prevent differential gear oil from
leaking around the O.D. of the
flange. An "O" ring seal is com-
pressed between the pinion flange
and the drive pinion to prevent
gear oil from leaking out through
the splines. See Figure 6-45.
6 - 1 2 REAR AXLE TROUBLE
DIAGNOSIS
a. Elimination of External
Noises
When a rear axle is suspected of
being noisy it is advisable to
make a thorough test to determine
whether the noise originates in
the tires, road surface, front
wheel bearings, engine, transmis-
Fig. 6-45—Rear Axle Assembly
sion, or rear axle assembly.
Noise which originates in other
places cannot be corrected by
adjustment or replacement of
parts in the rear axle assembly.
(1) Road Noise. Some road sur-
faces, such as brick or rough
surfaced concrete, cause noise
which may be mistaken for tire
or rear axle noise. Driving on a
different type of road, such as
smooth asphalt or dirt, will
quickly show whether the road
surface is the cause of noise.
Road noise usually is the same on
drive or coast.
(2) Tire Noise. Tire noise may
easily be mistaken for rear axle
noise even though the noisy tires
may be located on the front
wheels. Tires which are worn
unevenly or which have the sur-
faces of the non-skid divisions
worn in sawtooth fashion are usu-
ally noisy, and may produce vi-
brations which seem to originate
elsewhere in the vehicle. This is
particularly true with low tire
pressure. Some designs of non-
skid treads may be more noisy
than others, even when tires are
new.
(3) Test for Tire Noise. Tire
noise changes with different road
surfaces, but rear axle noise does
not. Temporarily inflating all
tires to approximately 50 pounds
pressure, for test purposes only,
will materially alter noise caused
by tires, but will not affect noise
caused by the rear axle. Rear
axle noise usually ceases when
coasting at speeds under 30 miles
per hour; however, tire noise con-
tinues but with lower tone as car