The rear axle housing associated with solid-axle rear
suspension consists of a central housing, or differential
carrier, and axle tubes, which enclose the drive axles and
extend to the rear wheels. (Vehicles with independent rear
suspension will not have axle tubes.) Rear axle housings
will have a vent to relieve pressure buildup. They will also
have oil drain and fill plugs. See Figure 16-26.
Most rear axle housings are made of steel. Steel axle
tubes are pressed and welded into the housing or are cast
integral with the housing. The axle tubes usually have an
integral flange at the outer end. The flange provides a
mounting surface for the brake backing plate and an axle
retainer plate.
Since the rear axle housing is a solid structure, it
moves up and down with the wheels as they move over
bumps and holes. To control this movement, the rear axle
housing is attached to the vehicle body through an
arrangement of springs, shock absorbers, and control arms,
Figure 16-27. These parts align the rear axle assembly to
the vehicle while isolating most of the axle movement.
Chapter 16 Rear Axle Assembly Construction and Operation 323
Rear axle
housing Drive shaft
Fill plug
Drain plug
Figure 16-26. Rear axle assemblies will almost always have fill
plugs but not necessarily drain plugs. On a differential without a
drain plug, the inspection cover or carrier must usually be
removed to drain the oil. Oil can sometimes be drained by
removing the lowest inspection cover-attaching bolt.
(DaimlerChrysler)
Drive
shaft
Differential
carrier
Brake line
Rear axle
housing
Vent hose
U-bolt
assembly
Brake assembly
Axle flange
Brake drum
Suspension
system leaf spring
Shock
absorbers
A
Figure 16-27. Two methods of suspending the rear axle assembly of a vehicle with a solid-axle rear suspension are shown. Both
methods involve the use of conventional shock absorbers. A—Leaf springs support and align the rear axle assembly. This method
simplifies the assembly, but makes the removal of the rear end difficult.
(continued)