498 Auto Fundamentals
This chapter describes the principles and
components of the steering system. Modern
steering systems are either parallelogram sys-
tems or rack-and-pinion systems. Both are avail-
able in manual and power-assisted versions.
Studying this chapter will prepare you for
Chapter 27, Wheel Alignment.
Steering System
The steering system is designed to allow the
driver to move the front wheels to the right and
the left with minimum effort and without exces-
sive movement of the steering wheel. Although the
driver can move the wheels easily, the transmission
of road shocks to the driver is typically minimized.
A steering system that transmits some of
the road shock to the driver is known as a semi-
reversible steering system. A steering system
that does not transmit any road shock to the
driver is referred to as an irreversible steering
system. A truly irreversible steering system
would make it difficult for a driver to follow the
grooves that naturally form in roadways,
increasing the stress on the steering system. For
this reason, semi-reversible steering systems are
used in most passenger vehicles.
Many types of steering systems have been
used in the past. Modern steering linkage
arrangements include rack-and-pinion linkage,
shown in Figure 25-1, and conventional linkage,
shown in Figure 25-2. This chapter will cover
the steering systems currently used. Although
there are some variations, all steering systems
have some principles and components in com-
mon. The basic steering system can be divided
into three main assemblies:
• The spindle and steering arm
assemblies.
Steering
arm
Outer
tie rod
Inner
tie rod
Outer
tie rod
Inner
tie rod
Rack-and-pinion
steering gear
Figure 25-1.
A rack-and-pinion steering system. Rack-and-pinion systems are much simpler than conventional steering systems,
such as the one shown in Figure 25-2. This rack-and-pinion uses an electric motor as a power assist.
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