Idler arm

Idler arm for a heavy-duty truck

On an automobile or truck with a conventional Parallelogram steering linkage, the Idler Arm or idler arm assembly is a pivoting support for the steering linkage.

The idler arm consists of a rod which pivots on a bracket attached to the frame of the vehicle on one end and supports a ball joint on the other end. Generally, an idler arm is attached between the opposite side of the center link from the Pitman arm and the vehicle's frame to hold the center link at the proper height. Idler arms are generally more vulnerable to wear than Pitman arms because of the pivot function built into them. If the idler arm is fitted with grease fittings, these should be lubricated with a grease gun at each oil change.