Idler arm definition
In a parallel relay-type steering linkage , it is one of the connecting levers. The steering gearbox is attached to a pitman arm which converts rotary motion to lateral motion. The pitman arm connects to a transverse centerlink which connects to the idler arm attached to the frame side rail on the opposite side of the vehicle. The ends of the centerlink connect to two adjustable tie rods that transmit the lateral movement of the centerlink to the steering arms at each steering knuckle .