40-60 MPH shimmy

[Jazzman]

Fellow Bimmernuts, I have read a lot about the dreaded shimmy at speed but please confirm if I have the same thrust arm problem. My shimmy (steering wheel shake) comes when I brake to slow down from speed. And the shake comes in at around 60 MPH down to 40 MPH as I am braking. I am going to replace the thrust arm in the very near future using BMA parts but if my problem is not related to the upper arm then I would like to know so I can get the other necessary replacement parts. I want to do the work all at one time, you know (I am getting old for this stuff, being a backyard mechanic for over 20 years). Thanks for all the help from the board and hello to all the San Diego threaders.

[jplacson]

Well, braking shimmy is most likely the thrust arm bushings... mine went away after I changed the bushings... but my 50-60 shimmy is still there... very mild...but still there.

Check your wheels... balancing... out of round.. hubcentric rings (I'm getting a set just to be safe)...alignment.

From what I've read, if you really, really, really, really wanna be sure... you're gonna be rebuilding the front suspension, including steering components... if that still don't work... do the rear... if that don't work... well... you might just have to live with it.

I'm trying hub rings first... if that doesn't solve my mild shimmy... I'm checking some steering components that I might've missed... then check my subframe mounts... then rear shocks... then nothing else seems to be wrong, it might just all go back to my thrust arm ball joints.

[Unregistered]

For a few months now my 530 has been shaking the steering wheel when I brake at around 40 to 60 mph I just replaced the front discs and the problem has gone completely. Looking at the old discs they appear to have some hair-line cracks in the friction surfaces. Incidently the price of discs here in England was £50 - £60 from a main agent . I got them from Eurocarparts at £12.50 each.
As a qualified engineer/machinist I have examined the cheap discs closely and I am well satisfied with the quality.

[Raz]

Just my 2p - I reduced my shimmy dramatically by inspecting each wheel, choosing the two with the least amount of balancing weights and putting them on the front. The result is 500% better and it cost nothing!

Worth a look :-)