2009 Mercedes CLS MOT, Wheel Bearing and Bush Repairs in Walsall
A 2009 Mercedes CLS came into us here at Platinum Vehicle Services for its MOT. The owner knew it needed to pass its test but had also noticed a low humming noise that seemed to get louder at higher speeds. That kind of noise is worth paying attention to, and once we got the car up on the ramp it became clear there was more going on beneath it than a straightforward MOT check.
The Wheel Bearing Had Worn Beyond an Acceptable Level and Was Flagging as a Safety Issue
When we inspected the wheel bearings, one had developed noticeable play and was generating the noise the owner had been hearing. A wheel bearing is the component that allows each wheel to spin freely on its hub. When it is in good condition you would not know it was there. When it wears, you start to feel and hear it. In this case, there was measurable movement in the bearing when we checked it by hand, which means the wheel was not sitting as firmly on the hub as it should be. On a vehicle travelling at motorway speeds, that is a genuine concern. A bearing that fails completely can, in a worst case, cause the wheel to seize or separate from the vehicle. At the stage this one was at, it was also putting additional load on surrounding components, which over time would have drawn more parts into the repair. Catching it at MOT stage kept the job contained.
A Worn Bush Was Causing the Suspension to Move in Ways It Should Not
We also found a worn suspension bush. A bush is a small rubber sleeve that sits between two metal parts in the suspension or steering system. Its job is to cushion movement and absorb vibration while keeping everything located correctly. When the rubber deteriorates, which it does gradually over time and is common on vehicles of this age, the metal parts start to contact each other directly. On this CLS the bush had cracked and lost its shape, leaving the suspension arm with more movement than the manufacturer allows. The effects of that are felt through the steering, the handling and the tyres. An out of tolerance bush causes uneven tyre wear, meaning the tyre wears faster on one edge than the other, which shortens its life and reduces grip in an emergency. It also causes a knocking sensation over uneven road surfaces. Left longer, the increased movement stresses the surrounding components and the repair scope widens. Addressing it alongside the wheel bearing, during the same visit, avoided a return journey and a second labour charge.
We Replaced the Bearing and Bush, Completed the MOT and Road Tested the Car Before It Left Us
We fitted a new wheel bearing to the affected corner and replaced the worn bush with a new rubber mounted unit. Once both repairs were complete we carried out the full MOT inspection and road tested the car to confirm the humming noise had gone and the steering felt as it should. The CLS left us with a clean MOT certificate and two faults resolved that, had they been left, would have cost more to put right and carried a growing safety risk the longer they were ignored.
What to Watch for on Your Own Car, and How to Book With Us in Walsall
If you notice a humming or rumbling sound that builds as your speed increases, particularly if it changes tone when you move the steering slightly left or right, that is worth having checked. It is a common sign of a wheel bearing starting to go. Knocking or clunking over speed bumps or rough road surfaces, or a car that feels vague or pulls slightly through a corner, can point to worn bushes. Neither of these faults tends to announce itself dramatically at first, which is why an MOT is often the point at which they get picked up.
At Platinum Vehicle Services in Walsall we work on Mercedes, BMW, Audi, Volkswagen, Ford and a wide range of other vehicles, covering everything from routine servicing and MOT testing through to suspension, brakes, engine work and complex diagnostics. We tell you what we find, explain what it means and let you make an informed decision. You can leave a message any time of day or night on 07970901354 and someone from the team will get back to you as soon as possible. To find out more about what we do or to get in touch, visit us at platinumvehicleservices.co.uk.
