1994 Mercedes-Benz S420 Steering Center Link Replacement Cost

For steering systems that use a steering gear or a power steering gear, the gear will be on one side of the vehicle, but turns both front wheels. To facilitate this action, a centerlink is used to transfer the push or pull from the steering gear to the other side of the front of the vehicle. It is just a solid piece of metal with a hole in each end so it can connect to the pitman arm and idler arm. It also has another set of holes on the ends for the tie rods. Some centerlinks have the ball joint installed directly in the ends, and are not serviceable.

To understand how the centerlink works, you must understand the pitman arm and idler arm. The pitman arm is connected directly to the steering gear on one end, and it connects to the centerlink on the other end. When the steering wheel is turned, the steering gear turns the pitman arm, which pushes or pulls the centerlink. On the other side of the vehicle, the centerlink is connected to the idler arm, which is bolted to the frame and centerlink, and turns with the centerlink whenever the steering gear pushes or pulls this assembly. With that knowledge, it should not be surprising to find that the centerlink also attaches to the tie rods, which push and pull the wheels when the steering gear turns. This is how a steering gear type front end operates, and goes to show how the centerlink received its name.

The centerlink will not typically wear out, as it is just a piece of metal with for holes, however, some types of centerlinks have ball joints installed on the ends instead of holes, and those ball joints can wear out, and necessitate replacement of the centrelink or end links. When one of the ball joints for the centrelink has failed, a clunking or popping noise will develop while turning, and the steering wheel will begin to feel loose and appear off-centered while driving. Also, physical damage to the centerlink calls for replacement, as a bent centrelink will distort the steering geometry of the vehicle, and typically the passenger wheel will point too far towards the centerline of the vehicle. This will be noticeable by feathering on the tire, and possibly extreme tire wear on the shoulders.