An integral carrier is constructed as part of the
axle housing. (T/F)
Rear axle ratio is determined by comparing the
number of teeth on the
number of teeth on the
Excess ring and pinion backlash can cause a
"clunking" sound when an automatic
transmission is placed in drive. True/False
often require a
lubricant that is compatible with friction
Ring and pinion preload is a common
differential adjustment. (T/F)
Learning Objective: Identify the parts of the rear drive
axle and front drive axle. List the function of the rear
axle. Compare the different types of axles. Describe the
procedures for replacing axle bearings and seals.
Axles are classified as either LIVE or DEAD. The
live axle is used to transmit power. The dead axle only
serves as a support for part of the vehicle while
providing a mounting for the wheel assembly. Many
commercial trucks and truck-tractors have dead axles
on the front, whereas practically all passenger vehicles
use independent front-wheel suspensions and have no
The shaft in a live axle assembly may or may not
actually support part of the weight of a vehicle, but it
does drive the wheels connected to it. A live axle is
involved with steering when it is a front drive axle.
Some live rear axles are also designed to steer. The rear
axle of conventional passenger vehicles is a live axle,
while in a four-wheel drive vehicle both front and rear
axles are live. In some six-wheel vehicles, all three
axles are live axles.
The axle housing may be of the one-piece or split
(banjo) type construction. The former, known as the
banjo type because of its appearance, is far more
common (fig. 5-22). Notice that openings, both front
and rear, are provided in the center housing. The front
opening is closed by the differential carrier, while the
rear is closed by a spherical cover plate.
Since the assembly must carry the weight of the
vehicle, the axle housing in heavy trucks and tractors is
a heavy cast unit. In light-duty trucks it may be a
combination of cast and steel tube; in general, the
center or differential and final drive case is a cast and
machined unit, whereas the axle housings themselves
may be welded or extruded steel tubing.
Items, such as brake backing plates, mounting
flanges, spring mounting plates, and accessory units,
may be riveted, welded, or cast into the axle housing.
Inspection covers are often provided through which
Figure 5-22.Axle assembly.