Mercedes-Benz W211 rear-end whine and driveline rumble
W211 what causes rear-end whine or growl?
The most common causes are the propshaft centre bearing bracket, the propshaft universal joint, the rear bearings or the differential. The rear end can also whine if the oils have never been changed. The noise may only be heard in a certain speed range, and replacing the propshaft bearing has stopped the noise.
W211 how do you locate the source of a rear-end noise?
The rear of the car is safely lifted into the air, started and put in gear, and a second person listens to the noise from under the car. If the noise comes from the middle of the car rather than from a corner, the cause is probably a rear bearing. Have a workshop do the test.
W211 what else besides the driveline should you check if the rumble continues?
The cause of the vibration and rumble may be elsewhere: a dragging brake, warped brake discs, an uneven or defective tyre and wheel, or the engine mounts. Vertical runout in the wheel does not show up in balancing. Brake work is safety-critical and a workshop must check the result.