Control arms are used to control wheel movement. Used on both front and rear suspensions, they are commonly referred to by their position, such as the upper and lower control arms. Common control arm configurations are shown in Figure 6-24 through Figure 6-26. Control arms are also called A-arms or wishbones due to their similarity to being A- or wishbone shaped.
A-arms typically have two connections to the frame and a ball joint for connecting to the steering knuckle. The control arm mounts to the frame with bushings. These bushings allow for up and down movement of the arm while controlling back and forth motion.
The bushings are generally rubber and steel and are pressed into the control arms. In addition to acting as pivots for the control arms, the bushings act as dampers, twisting and untwisting to return the control arm to its original position. Also connected to lower control arms are the stabilizer bar links. The stabilizer bar links join the lower control arms to the stabilizer bar. These links can be a set of bushings and washers or a solid link with ball-and-socket joints.
