Truck Parts & Their Functions

Steering

Item	Sample Picture	Function
Drag Link Assembly		A fixed-length drag link assembly connects the steering gear pitman arm to the axle steering arm. The ball stud and socket assemblies at each end of the drag link prevent binding when the relative angles of the pitman arm and steering arm change, which happens when the vehicle is steered or the front axle moves up or down.
Pitman Arm		Pitman Arms connect the steering linkage to steering column and supports the other end of linkage from the idler arm. Pitman arms also convert the turning movements from the steering gear box to the center link. They are responsible for the back and forth movement that actually steers your tires.
Steering Gear box		The steering gearbox contains the gears that transmit the driver's steering inputs to the steering linkage that turns the wheels, and it multiplies the driver's steering changes so that the front wheels move more than the steering wheel.
Tie Rod		The tie rod links both tie rod arms on the steering knuckles so that the steering knuckle turned by the gear also turns the steering knuckle on the other side of the vehicle. The tie rod assembly consists of a cross tube and tie rod ends. The ball studs are held to the tie rod arms by castle nuts and cotter pins. Like the ball studs on the drag link, the ball stud and socket assemblies at each end of the tie rod prevent binding when the relative angles of the steering components change.