First of all I have to disagree with you gentlemen...
First of all, I have to disagree with you gentlemen on your opinion of BMW
drivers (we don't ALL drive on the sidewalk!). I have a 1988 528e, and it has a
problem I cannot figure out. Sometimes, when I step on the brakes, the steering
wheel shakes and rattles. However, if I let go and step again on the brakes
right away, the shake is gone. I took it to a brake shop to check the rotors,
but there was hardly any warpage in them, front or rear. What is the problem?
TOM: It could still be warped disc rotors, Haz. You say there's "hardly any
warpage" in them, but it only takes a little bit of warp to make a lot of shake
-- especially at high speed.
RAY: But if you're satisfied that it's not the disc rotors, then I'd look for a
bad universal joint.
TOM: I've seen this on other rear-wheel-drive cars on rare occasions. What
happens is that the universal joints -- the flexible connectors that allow the
drive shaft to bend while it's spinning -- are fine under normal conditions.
RAY: But when you step on the brakes, particularly at high speeds, the geometry
of the whole car changes. The front end noses down, and you change the drive
shaft's angle. And if one of the u-joints is bad, it won't be able to bend
properly under those conditions and you end up with a "whole lotta shakin'
TOM: It's also possible that you have a bad ball joint or bad tie rod ends up
front. And since both of those could be serious safety problems, it's worth
having those components looked at carefully, too. But my guess is that when
your mechanic removes the drive shaft, he'll find a seized u-joint.
RAY: Unless you get lucky and free it up next time you hit a curbstone while
driving on the sidewalk, Haz!