Scary rumbling...

[wycoco]

Starting from first and continuing onto second gear, each time I accelerate there is a rumbling noise from the rear. After second gear and so on, it's fine. At first, I thought it was because the tires weren't gripping in first and second gear. They are pretty low on tread but definitely not bald, so I assumed the tires were slipping. Another guess at the time was that the rear driver side tire was really low on air. I filled it back up, but didn't solve the problem. The rumbling is so loud, it feels like the car is about to fall apart. I can't quite tell which side it is coming from. It sounds like both. A buddy of mine said he thinks it's the driver side.

Here's any extra info, just in case..

Bilstein shocks
3.73 LSD
Running spacers, but with long studs
Uhh.. not quit sure the offset or how big the spacer is..
The spacer looks about an inch thick.
but here's a pic..





Any ideas?

[ivo316]

Sounds like bearings, maybe your rear end, or in the tranny, I'm inclined to blame the tranny since you say it does it in first, please try in reverse and see what happens, if the noise is the same then it's the bearings on the first gear.

Please wait to hear other comments though, this comes from someone knowing about cars in general, i'm still new to E30's ;)

[PiercedE30]

C..........S.................B!!!!!!!!!!!!!!!
i say it's the CSB.....










Did I mention I think it's the CSB?

[wycoco]

Thanks guys, I'm going to look into it. Any others?

[jlevie]

Trying to remotely diagnose something like this is pretty futile, but as a WAG I'd suspect a bad driveshaft (binding u-joints) and the resultant damage to the center bearing. An experienced BMW tech should be able to identify the cause of the noise with a single test drive.

[Mike325]

I vote CSB and u-joints. And then, rear wheel bearings. Jack the rear of your car up and see if you can, with a long screwdriver, pinpoint where the noise is coming from.

[O 16581 72452 5]

Jack 'er up and wiggle the wheels...all four.

That's the quickest and easiest, move on from there to what these guys said if they're solid.

I notice you have aftermarket wheels, kind of a long shot, but maybe your wheel bolts are too long and rubbing? I had this problem, when i was traveling slow, it was very loud and obnoxious, but as i got over a certain speed, it kind of faded.