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Discussion Starter #1 (Edited)
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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Its a great feeling when problems are resolved! Just goes to show you that whoever coined: "Drive it like you stole it" must have known what they were talking about. Congrats.
 

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Tom,

My suspicions in the other thread were confirmed I guess. I think if you had done a "Zeckhausen" bed-in cycle (might have needed to do it a few times) you probably could have gotten rid the wobble. Anyway, I'm glad that all is well now, and I assume the wheels/tires are waiting at Leith for me to pick up? Glad they served the purpose of isolating the problem!! Back into storage they go. :)

Take care,
Chuck
 

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Good info, funny thing is DRM once told me the samething when he was giving me a ride in the S3. I guess even after break in it still can glaze over, a few good hard hits and all is smooth again.

Hard braking is a good way to keep the wife out of the car but the kids love it.
 

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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.
Yes! Uneven pad deposits on the rotors is frequently the cause of pulsing on the brake pedal or wobbling upon light to even moderate braking. But it's not always because you baby the brakes. A lot of times it's caused by driving fairly hard on the brakes, the coming to rest for a prolonged period, like at a stoplight, or to chat with a friend you happen to see on the street. The hot pads deposit material on the rotors at that spot, and presto, you have wobbling.

Now here's a related story. I have a thread elsewhere talking about a rumbling sound and thumping from the front end, which I originally thought was bad wheel bearings given my mileage (80k). But I had the bearings checked and my indy tech told me it wasn't them! There was not only a rumble and thump, but it was hard to come to a smooth stop. Felt like pad deposits but I knew it couldn't be it since I have new rotors and pads. So to confirm I swapped on a spare set of OEM rear wheels/tires onto the front (I already have the 3mm spacers and longer bolts). Not only was the rumbling/thumping gone, the brakes felt smooth as silk. So plainly I have a tire problem. Now I have to figure out if it's one or both tires.
 

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Discussion Starter #7
Tom,

My suspicions in the other thread were confirmed I guess. I think if you had done a "Zeckhausen" bed-in cycle (might have needed to do it a few times) you probably could have gotten rid the wobble. Anyway, I'm glad that all is well now, and I assume the wheels/tires are waiting at Leith for me to pick up? Glad they served the purpose of isolating the problem!! Back into storage they go. :)

Take care,
Chuck
Chuck.

Yes, they are at Leith and btw, the wheels are about immaculate.

Thanks again,

Tom
 

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Discussion Starter #8
Dont baby your brakes anymore, I dont want to hear about a set of rotors lasting you more than 40k miles again :cheers:
Yes, I'm done babying this car - at almost 160,000 miles, I think she's broken in by now.:)
 

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Good report... thanks!
:cheers:
Dave
 

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Thanks for the Nice report out on the mystery "wobble". Just got mine back from a $650 trip the dealer for bushings and alignment. Looks like all I need to follow that up with taking the long way home via express way and a few select back roads!. Many thanks.
 

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Thanks for posting the resolution Tranck.
A lot of people only posted the problem but they never around anymore to post the resolution... :cool2:

I had similar problem in the past, but it was not as severe as your. I wish I came across your post earlier. But here is my past issue and it turned out to be uneven pad desposit on the rotor. :)


Regardz,

J Irwan
 

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Nice write up and congratulations on getting a very annoying problem fixed.:cheers:
 

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I have the same Wobble but on a set of AP's

it's very annoying and I have tried the bedding in process but with no joy as yet.. Just started comming on strong in the last 1000m

before that there was nothing!

Anj
 
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