2017 Mercedes-Benz C43 AMG Strut Bearing Replacement Cost

The strut bearing is integrated into the front strut, and becomes part of the front mount when the strut is bolted to the vehicle. The bearing allows the strut to rotate easily, and reduces noise from rubber grommets squeaking against metal when the wheels are turned.

Worn rear struts result in diminished ride quality that might feel “soft” as the vehicle leans excessively during turns, and bounces over bumps. The shock absorber in the strut may leak when it is worn. The strut may also cause a knocking or rattling sound if it is worn, damaged, or broken. If the vehicle leans excessively in turns, and bounces up and down over bumps, the struts are likely worn. If the strut rattles or knocks over bumps, it may be broken. Lastly, the tires may being to suffer cupping. Cupping is the raising of individual tire treads, and can be felt by hand, and heard when driving down the road.

A vehicle with worn strut bearings can be driven, but the ride quality will be diminished, and, more importantly, the vehicle's handling will be compromised. A car's ability to remain level while turning, with traction spread between all four wheels, is dependent on the struts. As the condition of the struts worsens, the ability of the suspension to perform properly, especially in an emergency situation, also worsens.

Many manufacturers recommend inspecting the struts for failure during some periodic inspections, and others may specify when changing the struts is necessary. Nearly all vehicles will need to have them changed at some point, but rough driving habits may shorten the serviceable life of a strut. Struts may need to be replaced anywhere between 50k and 100k miles. If at any time the struts are leaking, broken, or damaged, they should be replaced immediately. Struts should always be replaced in pairs to ensure predictable and even performance.

Worn, damaged, or broken struts are diagnosed in a number of ways. If the vehicle has excessive play in the suspension, bounces easily up and down for an extended time, leaks fluid from the strut, or has cupping present on any tire, the struts are likely worn. Many times, a strut is diagnosed when a technician is replacing suspension or axle parts or during a four wheel alignment.

To change a strut bearing, a technician first needs to lift and support the vehicle, and remove the wheels. The brake caliper and rotor are removed and the sway bar link is disconnected. Several additional lines are often connected to the strut, and must be removed delicately to prevent damage to other systems. The technician then disconnects the strut from the steering knuckle and from the strut tower to remove it from the vehicle. If the entire strut assembly is being replaced, installation is relatively simple. On the other hand, it is common to reuse the coil spring from the old assembly. In this case, the worn strut will need to be compressed and disassembled, and the new strut will need to be assembled before it is installed. This includes placing the new strut bearing in the proper position before completing assembly. Many manufacturers recommend using a new strut mount when replacing struts, and if the strut uses a strut bearing, the bearing should be replaced.

RepairPal recommends replacing struts in pairs. The ride quality and performance of the vehicle will be significantly altered if the struts do not match in type and quality, and unpredictable driving conditions may result. Prior to replacement of the struts, a full inspection of the steering and suspension should be performed to identify any other needed repairs. This will cut down the labor costs when compared to replacing the worn parts separately. Also, we recommend a four-wheel alignment when struts are replaced. The new struts may change the vehicle's ride height, and will change the vehicle's wheel alignment.

All models do not use strut bearings. Most vehicles will use front struts designed with a bushing, especially vehicles up to the mid 2000's. If the vehicle does not use a strut bearing, noises from the upper strut will require the same basic procedure to replace the upper strut mount.

The strut bearing can be replaced at home with specially coil spring compressors, strut rod nut removal tool, and proper training. It is critical to understand coil springs are under tremendous tension, and can cause injury, maim, or cause death. If struts are not completely understood, as well as safety measures for disassembly, a professional technician should complete the repair.