Whether you drive a Porsche, Mercedes Benz, Audi, Mini, Volkswagen or BMW, your vehicle has four wheels that meet the ground and a drive system that takes the power from the engine and transmission and connects it to the wheels. Wheel bearings are incorporated at each wheel to allow the wheel to rotate on a virtually friction-free surface. Similarly, since the engine and transmission run parallel to the chassis, the power must go through a set of gears and turn ninety degrees to get to the drive wheels. This housing containing these gears is called a differential. The differential makes use of similar bearings as the ones used at the wheels to reduce friction.

As with any bearing, when a bearing begins to wear and fail, friction increases, metal material is worn down and noises (often very bad) can be heard. A failing bearing may make a whistle noise or a roaring grinding type noise. This noise will often change, getting louder as the vehicle’s speed increases or as load increases or decreases (acceleration, deceleration or turning). Often it is very difficult to distinguish the source of this roaring or grinding noise as it resonates through the chassis. There are some simple things that you can do to help distinguish between a failing wheel bearing and a failing differential.

Wheel Bearing Noise:

One of the simplest checks for a failing wheel bearing is to raise the vehicle so the wheel is no longer in contact with the ground. Once this is done, grab the wheel with your hands opposite one another and wiggle the wheel back and forth. If the wheel wiggles back and forth on the hub containing the bearing, odds are that your vehicle has a bad wheel bearing. You can also spin the wheel and listen carefully for a grinding or roaring noise. If you suspect a wheel bearing issue, German Auto Center of Austin has the expertise to repair your BMW or other German make vehicle so you’ll be back up and running properly.

Differential Noise:

The noise of a failing bearing within a differential is virtually the same as the noise from a failing wheel bearing, hence difficult to isolate. Unlike a wheel bearing, where the noise will change with wheel speed but typically will not change with variations in load (acceleration/deceleration), the noise heard from a failing bearing within the differential will make a roaring or growling noise on changes in load as well as changes in speed. Additionally, differential noise will typically not change when turning a vehicle right or left.

As a rule of thumb, if you are hearing any unusual noises at all, stop by and see the experts at German Auto Center to advise and diagnose before things get worse. A bearing that fails completely can cause extensive damage to other parts and components, significantly increasing repair costs. Wheel bearings and differentials on your Porsche, Mercedes Benz, BMW Audi or Volkswagen are subject to extreme heat and stress and as such are designed to be serviced.  Check and change your differential fluids regularly to avoid expensive failures.

Whether you drive a Porsche, Mercedes Benz, BMW, Volkswagen or Audi, it is important to remember that today’s German performance vehicles will serve you for many miles and years to come. Follow these simple suggestions and listen to Porsche, Mercedes Benz, BMW, Volkswagen and Audi service experts in Austin. If you have any questions, simply come by and visit Austin German automobile repair experts at German Auto Center and we will be happy to assist you!

German Auto Center

Our usual response time for quotes is 1-2 business days. If you need a quicker repair, please schedule an appointment. We'll offer estimates for your approval before proceeding with repair. Please understand that we only provide quotes for 2010 or newer vehicles. Older vehicles can have unpredictable repair costs. Thank you for your understanding.

Request A Quote