Quote:
Originally Posted by hdubf80
This is my only complain with the car. And for a $80,000 + car bmw needs to address this issue especially with all the money they make. I hope enough people complain about this so they provide us with a decent fix.
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There isn't really anything for BMW to do -- it is likely a matter of how you treat the brakes when brand new. I didn't see this issue on my F80, but have had other cars where i'd experience the 'shimmy' while braking from say, 70-50, sometimes so bad the steering wheel would shake.
to the best of my understanding, this is caused by clamping the (hot) brakes after a stop while they are new, before the pads have settled in. under these conditions, it can happen that a microscopic amount of the pad will transfer to the rotor and form an imperfection that is impossible to see, and only exhibits this behavior at certain speeds.
the only fix i know of is to replace the rotor (perhaps merely turning it will work -- i'm sure these are expensive rotors) and pads. then, for first few miles, be very careful not to sit at stoplights or elsewhere with the brakes clamped tight when they are hot. with the dct, this isn't too difficult, and it is what i did when the F80 was new. in my volvo, i simply use the handbrake after stopping to keep the car stationary.
after, say, 100 miles your pads/rotors should be well matched and this is no longer an issue. hope this helps.