Humming in rear of car

[Garageaholic]

I have this humming sound in the back of my 87 325e (just purchased as daily driver)... It only happens when i turn to the left,, not right....

And as i go faster, it whines kinda higher.... does anybody know what this is? am i rubbing on anything? or is it the differential?

[DoriftuEvo]

Diff noises usually change with throttle because more load is put on them during acceleration. I'm not a great troubleshooter, but maybe that helps a little.

[browntown]

like above, I'm not mr. super trouble shooter, but however unlikely, wheel bearings? stuck caliper?? ebrake mechanism partially engaged?

[lordofthewaters]

Sounds to me like the left rear wheel bearing is gonna need to be replaced. But like the others said, I too am not a mechanic. I just play one on weekends.

[delatlanta1281]

it is probably the wheel bearing, When mine went I thought it was the diff due to load and speed change, but it got worse and worse and started to whine at low speed. Best thing to do to troubleshoot is put it in the air engage it gear and listen to the bearings with a stethascope (spelling). Basically put the probe in the backside or the controll arm to hear where the humming is coming from. If it is your bearing do it asap, when you remove the bearing if the casing splits in two it will make the job even harder. The older the bearing the more possible it will be to break.
Oh are you running spacers?

[Garageaholic]

no spacers. this car is stock all the way.... could be the bearing. and if it is. i'm not replacing it until it breaks.. wheel bearings are a bitch to fix..

the car has only 160k on it.. could they fail that early?
my '86 325es had 291k on it and it still was fine... did the sport model come with better rear bearings too? lolol jk

[delatlanta1281]

Mine went at 170, or started going. I don't actually know the life expectancy of a bearing..... but I guess it would have to do with the type of shit the car has been through.

[Garageaholic]

true, and my car is a northeast car, so there ya go.. that's your answer....

[rs4pro3]

I would actualy replace it now versus latter. I drove my 85 318i with a bad bearing for a while before I replaced it. I had a shop to it and the bearing was so shot they almost had to take the whole arm off and have a machine shop press it out. when they put the puller on it the bearing just pulled into pieces leaving the outer race stuck hard in the arm.

[lordofthewaters]

It's not that hard to do with the correct tools. If you try to go in half-assed then it get to be a problem.