'98 M3 rotors - can/should they be re-machined?

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mcquarrie wrote:

Just the way they're made. Metalmasters like at least one 'warm-up' stop when dead cold. They don't work well unless slightly warm but in exchange, they resist glazing and 'bite' better at higher temperatures like you'd find on track. The Deluxe are a different compound more suited for street driving, but are fine for occasional track use as well. At least, that's what I hear. -- C.R. Krieger (Never ran Deluxes ...)
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quote from BMW North Scottsdale in Az - wear sensor, pads and rotors for all four wheels on a 98 M3.....$1067 + sales tax.
how does that compare to BMW dealers around the country? to your favoured third party provider?
remember these are OEM parts.
BTW M3 OEM rotors are NOT drilled according to my BMW dealer.
So I have non-OEM rotors on there now. Mmmm...are drilled rotors more susceptible to warp?
snipped-for-privacy@gmail.com wrote:

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<quote from BMW North Scottsdale in Az - wear sensor, pads and rotors <for all four wheels on a 98 M3.....$1067 + sales tax.
<how does that compare to BMW dealers around the country?
Not bad, assuming that includes labor. I paid about that 3 years ago for OEM brakes on my E46 328i at a dealer near Washington, DC.
Tom K.
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Tom K. wrote:

"Not bad" in that it's what most dealers would charge but I recently did all rotors, pads and parking brake shoes on a 7 for less than US$400 worth of parts. There's nothing peculiar about BMW brakes so any garage could do it. Having said that I'm sure the M3 brakes are more expensive but I seem to recall the US don't have the floating rotors so they're not as expensive as they could be.
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No, $1067 + tax for PARTS ONLY. No labor. So I'm guessing at least 2 hours to do the job, at a rate of at least $125 an hour puts another $250 minimum on top of that.
Tom K. wrote:

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So I looked at the brakes this weekend.
All the rotors and pads are well above the minimum thickness, and only the front rotors showed even a hint of warpage; 0.16mm was the maximum axial deflection I measured with the rotors mounted, max allowed is 0.20 mm. Does 0.16mm sound like enough to cause steering wheel shake?
Another thought; the shake seems to get worse at the end of my commute when compared to leaving my house. I took the above measurements when the brakes were cold. Can the warpage get worse during driving, then relax when the brakes are cold?
Another question regarding rotors. Between the two friction surfaces of the rotor, there are vanes or blades which I assume assist in cooling the rotor. Pardon the analogy but they remind me of paddles on a waterwheel, except they are facing the wrong way (compared to a water wheel). On the rotor, the edge of the vane closest to the outer edge of the rotor is actually the trailing edge (with respect to the direction of rotation). I would have guessed that this edge of each vane should actually be the leading edge to maximize air intake. Sorry for the convoluted description, but those of you who can visualize what I'm describing ( I hope there's at least one) will appreciate how hard it is. Which way should these vanes be facing? All four of my rotors are as described above.
mcquarrie wrote:

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Air intake is from the center of the rotor.

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So then the rotor is acting like an impeller, pulling air in near the center of rotation and forcing it out at the edge?
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mcquarrie wrote:

suspension wear which gets more pronounced the more you drive as the rubber warms up.
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No. I can't feel anything unusual in the pedal. All the shake is in the steering wheel.
I'm just surprised it only happens when I brake.
adder1969 wrote:

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Beyer Motor Works of Chandler Arizona diagnosed broken rear bushings, worn out tires, and both rear trailing arms were bent.
I knew the tires were done for but didn't realise that could cause vibration.
So $865 for tires, and $750 for the suspension work later, the car handles the way it should; no vibration or shudder.
And I can recommend Beyer as an alternative to BMW dealers in the Phoenix area.
mcquarrie wrote:

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derek snipped-for-privacy@hotmail.com wrote:

So now you'll know not to jump straight into suspecting the rotors next time.
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mcquarrie wrote:

No; you get the opportunity for a real bonding experience. Get the parts, tools, and *share an afternoon* with her changing the pads and rotors.

Personally, I don't think anything you do can guarantee these brakes won't squeal. There are a half dozen 'cures', but none is certain. It's an inherent characteristic of high performance disk brakes. You want quiet; get a Buick. -- C.R. Krieger (Been there; done that)
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if you have dust covers on the brakes, that may lead t owarpage, if not driving and braking as usual heats em enuff that if you hit a puddle, the sudden cooling effect will warp em. check to make sure theyre the front rotors or back ones. front rotors warping bad may give a lil shimmy in the steering or a slight nudge when braking accompanied by pedal pulsing. if not they may be the rear ones. have the sho check using a dial gauge if they have one, i have yet to see a shop that owns em.
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try bavauto.com theyre pretty good
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varan wrote:

I've heard this forever, even repeated it. But I'm now convinced this is essentially urban legend.
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Yes, they are drilled - it is an M3. So no machining then. Ah well. Cha-ching!
varan wrote:

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