Rack-and-Pinion Steering Gear

The recirculating ball steering gear has the disadvantage that it occupies a good deal of space, usually in the engine compartment. The rack-and-pinion steering gear was first developed for compact cars in which the engine compartment space was limited. The rack-and-pinion system has worked so well that it is currently being used in both imported and American compacts and intermediate size cars.

The basic parts of a rack-and-pinion steering gear are shown below. The steering wheel and steering shaft are connected to a pinion gear. The pinion gear is in mesh with a straight bar that has gear teeth cut into one side. The toothed bar is called a rack. When the driver turns the steering wheel, the pinion gear turns, causing the rack to move. This movement, in turn, is connected to a linkage that moves the front wheels.
The rack-and-pinion gear is mounted in a rack housing assembly. The steering linkage consists of two inner tie rods and two tie rod ends. The inner tie rod ends are attached to the steering rack ends. The outer tie rod ends are attached to the suspension arms on the steering knuckles. Rubber boots are used to cover and protect the inner tie rod assemblies from road splash.