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View Full Version : Chasing the brake shimmy


ILoveMPower
11-10-2008, 01:12 PM
Just overhauled my front-end, also installed eibach/bilstein setup on all 4 corners, car handles great but with a few issues

Threads on the strut
sleeve were damaged, the collar nut would not thread on all the way, got it on about 4 twists but it's still "clapping" when the strut decompresses. Also my strut bearings have seen better days, could this be the clap? It's only on the right side and seems to be as the suspension is decompressing.

Car has a vibration upon hard(er) braking, more noticeable at higher speeds and with increased pedal pressure. Have not yet done the rear subframe bushings or my motor and tranny mounts, hopefully will get those done this weekend. Could any of these be a contributing factor?

Also keep in mind I have terrible shitty snow tires on with a tread pattern that was clearly not designed for a smooth ride, perhaps this also could have something to do with the situation, as they were rotated for the first time yesterday as well.

Any input is much appreciated, the car feels really great and handling seems more linear than the M5's, and also a less bouncy ride. I'd like to get the suspension all buttoned up before I start work on the M30.

Thanks much,
- Jeremy

P.S. I'll get some pictures up once the springs settle a bit and I get some 3mm pads on there!
e34.535i.sport
11-10-2008, 02:12 PM
How are the thrust arms? Changing over to powerflex bushes recently sorted my brake shimmy right out... If all suspension components check out i'd look at the brake discs next. Do u feel it through the steering wheel? If so you would suspect something up front, if not then it's rear end troubles!
ILoveMPower
11-10-2008, 04:14 PM
How are the thrust arms? Changing over to powerflex bushes recently sorted my brake shimmy right out... If all suspension components check out i'd look at the brake discs next. Do u feel it through the steering wheel? If so you would suspect something up front, if not then it's rear end troubles!

Yes I have just replaced thrust arms with lemforder pieces and the 750iL bushing, and I feel it in the steering wheel. I suppose it could be the rotors although they didn't seem to be too worn when I had the front end apart yesterday. I'm no brake expert, how can I tell if they are still good?
ILoveMPower
11-10-2008, 06:25 PM
I did not change the idler arm + bushing, could this cause a vibration upon braking? I already have the part, just need some more hrs to get the job done!
RobPatt
11-10-2008, 09:35 PM
..and yeah, I've been there... but if it's going on when you're braking... then probably has to do w/brakes...(get new rotors/bads). True, there's more pressure etc on the bushes under breaking, but you've already addressed that....

compared to what you've already done, rotors/pads are cheap, quick, and easy....






I did not change the idler arm + bushing, could this cause a vibration upon braking? I already have the part, just need some more hrs to get the job done!
632 Regal
11-10-2008, 11:36 PM
strut loose will cause the shimmy.