A pitman arm is used on vehicles with conventional suspension systems and parallelogram steering. As a linkage attached to the steering box (see recirculating ball) sector shaft, it converts the angular motion of the sector shaft into the linear motion needed to steer the wheels. The arm is supported by the sector shaft and supports the drag link or center link with a ball joint. It transmits the motion it receives from the steering box into the drag (or center) link, causing it to move left or right to turn the wheels in the appropriate direction.
This type of suspension and steering arrangement is used on virtually all rear-wheel-drive vehicles and many light trucks.