11-14-2012, 09:18 PM
Officially Welcomed to the 'Fest
Location: Ontario, Canada
Join Date: Jun 2010
Mein Auto: 530i 2003
Edjack gave you the the best advice in the 2nd post. Renew the thrust arm bushings.
Originally Posted by mikeson
Here is an update.
I replace all brake disc to OEM new one.(and yes, I replaced pads as well)
And all control arms and bushing are tight and stiff.(I try to shake and move but they seems very tight)
However, I still have a front wheel shaking sometime when I brake. No shaking on low speed.
Like 50 ~ 60m/h and apply brake, it shake little bit.
Wheels? and tires
? it has been balanced and did alignment.
ABS unit? it has been replaced by ABS unit fail.
Does anyone have an idea?
I know it seems counter to normal experience that suspension bushings would cause a shake under braking ... but that's the way it is with E39s. The E39 multilink front suspension is not a common configuration, so the common wisdoms don't work. This isn't to say that every brake shake is caused by the bushings. But for these specific symptoms the answer is virtually always the infamous thrust link bushing. This cause and effect has been confirmed time after time as described in the links that Bluebee gave you.
There is no test method to check the bushings, unless you get lucky and are able to see leaking fluid. Rather, one knows that the thrust link bushings are shot when the symptoms you described are present. BMW's TIS lists these bushings as a cause & also says that there is no check available.
FWIW, I am speaking with the voice of experience. I had the symptoms, checked my brakes again although they had less than 500 miles when I bought the car, checked the bushings visually and by push - pull, etc., etc. Everything was good ... except the driving results. I finally renewed the bushings and the shake disappeared.