Mercedes-Benz W210 front wheel bearing
How do you recognise a worn front wheel bearing on the W210?
The bearing growls or hums while driving, and you may hear rattling over potholes. To check by hand: lift the front end, spin the wheel and test for play. Once the noise is audible, the bearing should be replaced soon, because it can fail quickly.
How is the W210 front wheel bearing play adjusted?
The front bearings are tapered roller bearings that are not tightened to a preload but adjusted to be almost free of play. The reference value is 0.01–0.02 mm, and the wheel must turn freely without binding. A bearing that is too tight wears out and fails, so the tightness is checked carefully.
Should an old bearing be re-tightened or replaced with a new one?
A bearing that has already been tightened once and is worn should not be tightened again; the whole bearing set is replaced. A wrongly tightened bearing can damage the hub and the stub axle. The bearing races are pressed in evenly, not hammered. The job involves the brakes, so it is safety-critical and a workshop should check the result.