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5-4
DESCRIPTION
REAR AXLE ASSEMBLY
(174)
5-2 DESCRIPTION OF REAR AXLE
The rear axle assembly is the semi-floating
type in which the load is carried on the axle
shafts through bearings enclosed in the axle
housing. See figure
'5-1. It
has a torque tube
drive and a Hypoid type spiral bevel ring gear
and pinion set in which the centerline of the
pinion is below the centerline of the ring gear.
See figure 5-18.
The torque tube is joined to the differential
carrier to form a unit assembly called the third
member housing; the torque tube and carrier
are not serviced separately. This is because a
straightening operation is necessary to line up
the pinion bearing holes with front flange pilot
on torque tube. The third member housing is
bolted to the banjo type rear axle housing. Two
rear axle strut rods form braces between the
front end of the third member housing and the
outer ends of the axle housing to hold third
member square with axle housing. The torque
tube encloses the propeller shaft which is rig-
idly connected to the pinion through a splined
joint and a pin. See figure
5-1.
The pinion is supported in the differential
carrier by one or two Hyatt roller bearings
(rear) and a New Departure double-row radial-
thrust ball bearing (front) which is secured to
the shaft by a large lock nut staked in place.
One roller bearing was used during most of the
1948 model production. The last 1948 models
and all 1949 models have two pinion roller
bearings. 1948 model rear axles having two
roller bearings are identified by letters "BB"
stamped on bottom center of the rear axle
housing.
The pinion and bearing assembly is held in
position by 'a pinion bearing lock sleeve and
three cone-pointed lock screws which clamp the
double-row ball bearing against a shoulder in
the carrier. Shims placed between the bearing
and the shoulder provide correct relation of the
pinion with ring gear. See figure
5-1.
The ring gear is riveted to the differential
case which is supported in the differential car-
rier with two differential side bearings.
Threaded adjusters bearing against the outer
races of the side bearings provide means of
adjusting ring gear lash. The differential case
also houses two differential bevel side gears in
mesh with two differential bevel side pinions
mounted on a shaft which is anchored in the
case by a lock screw. See figure
5-1.
The splined inner ends of the axle shafts are
supported by the differential side gears. "Horse-
shoe" washers retain the axle shafts in the side
gears; washers are held in recesses in side
gears when differential pinion -spacer is in-
stalled. The pinion spacer is located between
the inner ends of the shafts and controls end
play of axle shafts. The outer ends of the axle
shafts are supported in the axle housing by
Hyatt roller bearings. Seals are provided on
both sides of each roller bearing to exclude dirt
and to prevent leakage of oil upon the brakes.
Rear axles used with Syncro-Mesh transmis-
sions are equipped with either standard or op-
tional gear ratios. See paragraph
5-1.
The rear
axle ratio is indicated by numbers stamped on
the underside of axle housing.
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