Steering Glossary
Adjusting sleeve: An internally threaded sleeve located between the tie rod ends. The sleeve is rotated to set toe in/toe out.
Ball and socket: A term often used for tie rod end.
Idler arm: A pivoting component that supports the right side of the steering relay rod in much the same manner as the pitman arm supports the left side.
Knuckle: A term used for steering knuckle.
Pinion: A small gear such as at the end of the steering shaft of a rack-and-pinion steering system.
Power steering: A power assisted steering system that uses hydraulic pressure to increase the torque (turning effort) applied to the steering wheel by the driver.
Power steering fluid: Special hydraulic fluid formulated to withstand extremely high system pressures and temperatures.
Power steering pump: A hydraulic pump driven by a belt from a crankshaft pulley to provide up to 1,300 psi (8,964 kPa) boost pressure necessary to operate the power-steering system.
Rack and pinion: A type of steering assembly that has a gear or pinion at one end of the steering shaft engaging a horizontal-toothed bar or rack having tie rods at either end that are attached to the steering arms.
Return hose: The low-pressure hose in a power-steering system through which fluid returns to the pump reservoir after leaving the steering-gear assembly or control valve.
Road feel: A term that relates to the driver's ability to sense the vehicle directional control from the movement transmitted through the steering wheel by the front wheels; not so sensitive on power-steering-equipped vehicles.
Shimmy: A harsh, side-to-side vibration of the steering wheel usually due to front wheel imbalance.
Steering arm: An arm that is attached to the steering knuckle that turns the knuckle and wheel for steering.
Steering axis: The vertical line through the centerline of the upper and lower pivot- or ball-joints on a steered wheel.
Steering column: Tubing through which the steering shaft mounts and rotates, providing a surface for the mounting of the hazard switch, turn signal switch, ignition switch, and transmission selector or shifter.
Steering kickback: The shock felt in the steering wheel as the front wheels encounter obstructions in the road.
Steering knuckle: The part around which each front wheel pivots as it is steered.
Steering linkage: The assembly of tie rods, idler arms, and links that transfer steering motion from the steering gear box to the steering spindles with the rods, pivoting joints, and supporting parts that transfer steering motion from the pitman arm to both knuckle arms.
Steering lock: A locking device on the steering column that prevents steering wheel rotation and/or selector lever motion unless unlocked using an ignition key.
Steering ratio: The ratio of the rack to the pinion.
Steering system: The mechanism that permits the driver to change vehicle direction by turning a wheel inside the vehicle.
Steering wander: The tendency of the steering to pull to the right or left when the vehicle is driven straight ahead on a smooth road surface that may be caused by improper caster adjustment.
Steering wheel: The wheel, located at the top of the steering shaft, which the driver uses to steer the vehicle.
Tie rod: The linkage between the idler arm or pitman arm and the steering arm.
Tie-rod end: A pivoting ball-and-socket joint located near the outer end of the tie rod used to connect the tie rods to the center link and to the steering arms.
Torque steer: An outside influence, such as uneven front tire-tread wear, causing the steering wheel to turn right or left during hard acceleration, relating to the dual torque and steering requirements that are applied to the drive axle of front-wheel-drive vehicles.
Turning diameter: The diameter of a circle a vehicle would make if the steering were locked.
