Figure 1-21. It is a hollow metal tube with two or more
universal (swivel) joints. The universal joints allow the
rear suspension to move up and down without damaging
the drive shaft.
Rear Axle Assembly
The rear axle assembly contains a differential and
two axles. The differential is a set of gears and shafts that
transmits power from the drive shaft to the axles. The
axles are steel shafts that connect the differential and
drive wheels, Figure 1-21.
Transaxle
The transaxle consists of a transmission and a dif-
ferential in a single housing. Although a few rear-wheel-
drive vehicles are equipped with transaxles, they are
most commonly used with front-wheel-drive vehicles,
Figure 1-22. Both manual and automatic transaxles are
available. The internal parts of a modern transaxle
assembly are illustrated in Figure 1-23.
Front Drive Axles
The front drive axles connect the transaxle differen-
tial to the hubs and wheels of the vehicle. These axles are
equipped with constant-velocity joints, which allow the
front wheels to be turned to the left or right and to move
up and down.
16 Section 1 Introduction to Automotive Technology
Figure 1-20. An automatic transmission serves the same
function as a manual transmission. However, it uses a hydraulic
pressure system to shift gears. (Ford)
Torque converter
(fluid clutch)
Bands Gearsets
Output
shaft
Transmission
case
Shift lever
Valve
body
Clutches
Oil
pump
Figure 1-21. The drive shaft sends power to the rear axle assembly. The rear axle assembly contains the differential and two axles
that turn the rear drive wheels. (Lexus)
Engine
Universal-joint
Transmission
Differential
Drive
shaft
Drive
wheel
Rear axle
assembly
Transverse
(sideways)
mounted
engine
Front drive
axles
Transaxle
Figure 1-22. Front-wheel-drive vehicles do not have a drive
shaft or a rear drive axle assembly. The complete drive train is
in the front of the vehicle. (Ford)