|STEERING SYSTEM OVERVIEW
by Mark Davidson
POWER STEERING PUMP
The power steering pump provides the hydraulic pressure used for steering assistance. The power steering pump is driven by a belt attached to the crankshaft pulley. The power steering pump pulley rotates a vane assembly inside a pump ring located inside the pump. Pressure is created by compressing fluid between the vanes and the surface of the pump ring. The pump pressure output is maintained by a flow control valve that contains an internal pressure relief valve. There are two types of power steering pumps used, submerged and nonsubmerged. Both are similar in operation, with the only difference being the type of fluid reservoir used. A submerged type of pump contains the pump and fluid reservoir in one unit. A nonsubmerged uses a remote fluid reservoir for the pump.
The steering column is a link between the steering wheel and the steering gear. It consists of a collapsible housing containing a collapsible rotating shaft. As a safety measure, the steering column is designed to collapse in the event of a front end collision. If a steering column has collapsed, it must be replaced. The steering shaft is a two piece component located inside the steering column. It is supported at the top and the bottom of the steering column by bearings. The steering column housing may also contain transmission shift components. Design of transmission shift components can vary from model to model. Earlier models use a tube that contained a rod that runs the length of the column used to actuate shift linkage. Recent model vehicles use a cable operated shift linkage, that can be actuated by a column mounted shift lever. Safety designs on late model vehicles incorporate a brake transmission shift interlock system. This system locks out shifter operation, when the ignition is on, until the brake pedal is depressed. Most systems use an electric solenoid actuated by the brake light switch, that releases the shift linkage. The steering column is used to mount several accessories. The turn signal switch, headlamp dimmer switch, wiper switch, and ignition switch, can be located on or inside the steering column. Service of the steering column usually requires removal of these components. Care should be taken when the steering column is removed for service. The column should not be dropped, leaned on, or subject to blows to either end. Internal components of the column can shear off, causing the column to partially collapse.
The tie rods are used to link the steering gear to the steering knuckle. The tie rod ends are a ball and socket design that allows the tie rod to flex up and down with the movement of the front suspension. Tie rods should be inspected for excessive movement, grease seal tears, or any visible wear. You should not be able to collapse the ball and socket assembly of the tie rod by attempting to compress it by hand. Any inward movement of the ball and socket should be considered excessive wear.
gave up on sports when the Browns left Cleveland and now spends his
Sundays working under a shade tree in the back yard tuning his son’s
soap box derby car.)