Chapter 9 Steering Systems 179
Conventional Steering
Conventional steering systems are sometimes referred
to as parallelogram steering, Figure 9-24. The conven-
tional steering system has more components than the rack-
and-pinion system. The basic design and components of
the conventional steering system are discussed below.
Conventional Steering Gears
All steering gears used on conventional steering
systems appear similar when viewed from the outside. All
contain a worm shaft, or worm gear, which is turned by
the steering shaft, and a sector gear, which is turned by the
worm gear. The interaction of the worm and sector gear
converts the rotation of the worm into movement at the
pitman arm while turning the steering effort 90°.
One difference between conventional and the rack-
and-pinion steering gears is that the conventional gear can
be adjusted. There are two adjusting devices built into the
conventional gearbox, as shown in Figure 9-25. The
adjuster at the top of the sector shaft is used to adjust the
clearance between the sector gear and worm gear. The
worm gear adjuster is used to adjust the bearing preload of
the worm gear. The worm gear adjuster can also be
Locknut
Outer tie rod
Inner tie rod
Threads
Figure 9-23. Exploded view of a manual rack-and-pinion steer-
ing gear assembly. Note that the inner tie rod end threads
(screws) into the outer tie rod end and is secured with a locknut.
(General Motors)
Steering wheel
Steering column
Lower steering shaft
Pitman arm
Center link Tie rod
Steering
knuckle
Idler
arm
Parallelogram
steering linkage
Steering gear
Tie rod
Figure 9-24. Parallelogram steering system. (General Motors)
Toe adjustment is made by loosening the locknut and
turning the inner rod to shorten or lengthen the tie rod
assembly.