Cotter pin
Nut
Bolt
Crossmember
One-piece
bushing
Retainer
Nut
Inner tie rod end
Locknut
Outer tie
rod end
Ball joint
Steering
knuckle
Figure 9-22. Rack-and-pinion steering linkage. Note the outer rod ends, which are attached to the steering knuckle with a ball joint.
This unit is hydraulic power unit. (Moog)
178 Auto Suspension and Steering
Rack-and-Pinion Construction
The body of a rack-and-pinion steering gear is usually
an aluminum casting. The rack is often held to the vehicle
body or frame by two U-shaped brackets that are bolted in
place. Other units are bolted directly to the vehicle with a
series of bolts and nuts that pass through holes in the rack
body and the vehicle’s frame. The pinion assembly is a
hardened steel gear supported by bearings at the top and
bottom. The rack is also made of hardened steel and moves
in slide bearings. Seals keep the steering gear lubricant
from leaking out of the rack-and-pinion assembly.
Figure 9-21 shows a typical manual rack-and-pinion gear.
Power rack-and-pinion gears will be discussed later in this
chapter.
Rack-and-Pinion Linkage
Rack-and-pinion linkage connects the gear to the
steering knuckles. Rack-and-pinion linkage is simple,
consisting of inner and outer tie rods, Figure 9-22. Design
of the outer tie rod was discussed earlier in this chapter.
One end of the inner tie rod is inside the steering gear and
is usually threaded into the end of the rack. A plastic or
metal shear pin keeps the tie rod from loosening. Some tie
rods are held in place by a crimp on the inner part of the
tie rod assembly. The inner tie rod is protected from the
elements by a flexible rubber bellows, sometimes called a
bellows boot or a boot. The outer part of the inner tie rod
is a threaded shaft. The outer tie rod is threaded onto this
shaft and held in place by a locknut, Figure 9-23.
Bolt
To steering
wheel
Universal
joint
Pinion gear shaft
Boot
Outer tie
rod end
Nut
Cotter pin
Grommet
Mounting bracket
Bolt
Nut
Bracket
Grommet
Cotter pin
Ball joint
Inner tie rod end
Gear housing
assembly
Figure 9-21. One type of manual rack-and-pinion steering assembly. Styles will vary. (Toyota)