In an automotive car or truck with conventional parallelogram steering, a Idler Arm or Idler Arm Assembly is a pivoting support for the conventional suspension systems and parallelogram steering. This type of suspension and steering arrangement is used on virtually all rear-wheel-drive vehicles and many light trucks. A few vehicles use two idler arms.
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.
Purpose: 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 (cross rod) at the proper height. Idler arms are generally more vulnerable to wear than Pitman arms because of the pivot function built into them, helping the pitman to move in the direction controlled by the steering gear. If the idler arm is fitted with grease fittings, these should be lubricated with a grease gun at each oil change.
Maintenance Tips/Suggestions: The idler arm should be lubricated at every oil change. The idler arm, along with other suspension components, should be inspected annually along with a complete wheel alignment. The most common vehicle symptoms associated with a worn idler arm include wandering, tire edge wear, and loose or erratic steering. Idler arm inspection techniques and specifications vary; have your vehicle inspected by a qualified service professional.
