On the other thread, I said that the next step toward resolving this very frustrating problem would be to put on a borrowed set of Michelin PS1's and front wheels from fellow board member CSBM5 (Chuck) because I felt certain that it HAD to be the tires.
Just to review, when this 1st started to occur, about 30,000 miles ago I would guess, the dealer - Leith BMW in Raleigh, NC put new rotors and barke pads on the front being the original at around 130,000 miles - shows I really babied the brakes right? - I'll come back to this very important point.
Installing the new rotors fixed the problem but, it came back probably 15,000 miles later I would again guess.
This time, installed the BMW X5 bushings because of a thread on this board that said that they were more substantial than the regular ones on the M5 - very little improvement.
The dealer had the car for a week about two weeks ago trying to fix this problem but, to no avail - installed new bushings again since they were under the two year parts warranty - did a "run out test" on the brakes and my tech Nathan said that it was within .001 tolerance whatever that meant - bushings had no effect on the problem.
So, I had the tech put the PS'1's wheels from Chuck - went about 20 miles - wobble wobble.
So, that would be 3 entirely different sets of wheels and tires, two new sets of bushings, had the entire front suspension replaced except for the ball joints so, it HAD to be either the rotors or the calipers right?
It was the rotors - sort of - I'll explain:
I told my tech that since the rotors would still be under warranty like the bushings to replace them and if THAT did not resolve it then I would go ahead and replace the calipers and if THAT would not resolve it, sadly, I was going to put a car cover over it and park it.
My tech Nathan put the new rotors on but he said that he thought that there was no way that they could possibly be the problem again, since he did the "run out" test.
He took the car out to "bed" in the new rotors - I get in the car - drive it home - about an hour and a half - testing the brakes many times - smooth as silk!!!
Here's what happened - as I was driving the car home, my tech said that he called one of his friends who works at another shop asking him for any answers to this problem - now, keep in mind, when the car was in the shop for the week, the shop foreman looked at the car etc etc -couldn't come up with a solution.
Here's what my tech's friend said - he had a car with a very similar problem as mine and a driver who babied his car like me and he told my tech that his "fix" was to take the car out and beat the living you know what out of the brakes - standing on them about 5 times and when he got done with that, no more wobble.
What happens according to both of these techs is that when you baby the brakes, the pads can get glazed unevenly resulting in uneven pad wear.
When the new rotors were installed on my car, my tech said that the new rotors have a rough surface and when he "bed" them in, it removed the glaze on the pads.
This made perfect sense to me and when I called him to tell him that the problem was resolved, he said that he thought that it would since on the way home is when he called his other tech friend.
Very long story short, if you HAVE installed new bushings and you steering wheel still wobbles under brakeing go and make some serious brake dust and if that does not work, have your tech clean up the pads and your problem should be over.
Mine finally is!!! and a very big Thanks to CSBM5 - Chuck - look for a PM from me.
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