BMW 318 Diagnose Rear Bearing Noise
“I have a 93 BMW 318is with 46000 miles.. i am hearing a roaring noise from the rear.. with the windows down and driving past a wall i can hear a metallic rubbing sound.. very light though.. i have jacked the car up and tried to see if there is play in either wheel and there is none.. are there any other things i should check before doing these bearings? diff fluid is full as well.. thank you..”
Either the axle bearings OR the rear end differential bearings are going out. Go about forty five on a safe road with no people and swerve to the left, and then to the right. If the noise quiets down when you go left, then the right bearing is worn. If it quiets down when swerving right, then the left bearing is worn. If the noise doesn’t change at all swerving to either side, then odds are the differential bearings are worn (and those BMW rear ends cost a TON.) Let’s hope it’s only a wheel bearing.
Assuming it’s the wheel bearing needing replaced, should I stop driving on it until I get it fixed?
Wheel bearings take a LONG time to actually wear out. I’ve seen guys drive six months on them, and they end up roaring like an old B 17 Bomber, but they still go down the road. If you pull on the wheel and it doesn’t wobble, you’ve got a long time before you absolutely have to replace the bearing.