Need help pinpointing vibration on a 2000 323i auto steptronic

I have a 2000 323i steptronic transmission, am33. 109689miles
I have a intermittent vibration that feels like it's coming from the rear. I thought it was coming from the right rear tire but my girlfriend swears it's coming from the left rear tire so that makes me think it's starting at the diff. The best way I can describe it is it feels like I'm hitting a rumble strip for a second and the car pulls back. You can feel the resistance in the rear end and the tach drops in rpms. I made a video of the tach when it happens, this is a less severe occurrence then normal but I frigured a video would help more than me trying to explain it. Any help is appreciated. Thanks in advance.

I should also mention that there are no codes and the vibration occurs in all tranny modes, d, s d, and m. I thought it was the transmission for awhile but it doesn't do it under acceleration. It only seems to do it when i'm driving at a steady rpm.

I got under the car today and checked all 19 or so bushings but I'm not really sure I'm checking them right. I was just looking for play. I tried to shake the upper and lower control arms, the trailing arms, even the shocks but everything feels solid. I can take pictures and/or video if that would help anybody. This is bothering the hell out of me. Oh I also checked the flex disc just out of curiousity. It looks dry rotted on the egdes but it seems solid. Any suggestions?

Thanks for all the "help" guys. Found the problem. Think I can press a new one in with a c clamp, alot of patience, and a breaker bar?




hope this helps someone else.

Originally Posted by Pantera7000

Thanks for all the "help" guys. Found the problem. Think I can press a new one in with a c clamp, alot of patience, and a breaker bar?




hope this helps someone else.

MIStool.net made a special tool for this job.

I don't see why the diff bushing would cause the axles to intermediately stop like that.

it sounds the diff is about to go. has it been leaking? check the level in there?

I had trouble understanding that too but this is the only thing I've noticed that seemed out of the ordinary. The diff doesn't leak at all. I'll check the level later today. How will I know if the diff is on it's way out?


Wait... are you talking about in the video? In that video the dsc was on. I didn't realize I had to take it off until after the video was taken.

Also $90 just seems like way to much to pay for a job were the bushing is only $25 and I'll only do it once. Call me cheap.

Wow...i have been having this problem for about a year now and got totally lazy to go to a shop to check it out!
Exact same issue...acceleration is fine, but when i am going steady on the road at a constant speed, the tachometer drops and go up, drops and goes up, and so on. During this, there is an intermittent vibration, EXACTLY like going over a rumble strip.

Thanks to your post, i know what it is now!!! How much do you think the repair is from a shop?

I've read anywhere from $800 to $240 on different forums. I'm gonna go check with autozone and advance auto to see if they have a rental tool. It's a long shot but it's worth a shot. I tried to do the bushing without dropping th diff and without unbolting the control arms....long story short it was 28 degrees with the wind chill and i got a far as the rear sway bar before i realized the subframe was in the way and i couldn't do anything. Not the best experience i've had.

I hate to be the barer of bad news but I replaced my rear diff mount bushing and things have only gotten worse. The intermittent vibration is still there only worse but not only that I have a constant vibration all the time now. My new theory is it's a drive axle. left side.

It sounds like it could be a frozen caliper. I had the same intemmitent problem. As soon as you stop after experiencing the vibration feel each of your wheels the wheel thats hot is the one that needs a new caliper. Hope this fixes your problem. I wasted a lot of money trying to figure this out.
You'll also see alot of brake dust on that wheel.

I have had this same vibration at constant speed about 1200 rpm's or so, alot of other people i have spoken to on here have the same problem. i just live with it its been going on for a while and bmw says there is no problem they can find, so if you come up with a solution let me know good luck.

Drive axles can be rebuilt locally for around $50, or you can get a new one but they're big $. Did you inspect your guibo while doing the differential bushings?

rotated tires. checked the flex disc, dry rotted on the edges but looked good. The drive axle is only $105 on autohaus. I've replaced the left rear caliper and checked the right rear and it's good. I wish it were a seized caliper. If it doesn't go away after the driveaxle I'm gonna do the rear trailing arm bushings and then probably the control arm bushing. This is eating me alive.

torque converter lock?

update: changed out the rtabs to uuc rtabs. also changed the rotors thinking that was it but no luck. $130 dollars and a chemical burn later nothing.