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Brake squeal is driving me nuts...

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Old 06-11-2016, 07:11 PM
  #16  
Jnosol
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Originally Posted by LexVan
I was always taught to keep car in gear for evasive/emergency reasons around red lights, intersections, and stop signs and such.

I get well over 100k miles out of clutches and over 75k on brake pads.
Yep. Match rev to the lower gear to slow down (engine brake), always be in gear then squeeze brakes to stop when needed. Never lightly ride the brakes to a stop, that wears the brakes prematurely. DCT makes it easier, but same concept.

For manual, as long as you know how to match rev there's nearly no clutch wear. Some P-Cars match rev in sport mode automatically.
Old 06-12-2016, 12:38 PM
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Originally Posted by LexVan
I was always taught to keep car in gear for evasive/emergency reasons around red lights, intersections, and stop signs and such.

I get well over 100k miles out of clutches and over 75k on brake pads.

This. Plus, if I can't do the perfect blip downshifts at each and every stop to show the kids how much practice they need, what's the point?
Old 06-12-2016, 07:08 PM
  #18  
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À propos nothing in particular -- I tend to hear (more feel with my left foot than hear, in truth) a slight squeak when releasing my clutch. Only time to time, and usually at low speeds/revs when downshifting (think crawling in traffic). Do you think it is evidence of an imperfect rev match or just general mechanical craving for some lube (clutch helper spring? something else)? I guess I'll ask the tech at the next service, but if my technique is at fault I can fix it sooner

On my last car (E93) sloppy rev matching usually manifested in a slight shudder but never noises...
Old 06-13-2016, 02:30 PM
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Originally Posted by ...Max...
À propos nothing in particular -- I tend to hear (more feel with my left foot than hear, in truth) a slight squeak when releasing my clutch. Only time to time, and usually at low speeds/revs when downshifting (think crawling in traffic). Do you think it is evidence of an imperfect rev match or just general mechanical craving for some lube (clutch helper spring? something else)? I guess I'll ask the tech at the next service, but if my technique is at fault I can fix it sooner

On my last car (E93) sloppy rev matching usually manifested in a slight shudder but never noises...
I cannot say I've experienced this in my 991, even after poor rev matching. I note that I always rev match in neutral while changing gears (as opposed to keeping the clutch in and rev matching).
Old 06-13-2016, 02:50 PM
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Originally Posted by ispool
I note that I always rev match in neutral while changing gears (as opposed to keeping the clutch in and rev matching).
Wait... do you mean you double-clutch the 991? Or that you clutch in, switch to neutral, rev match, switch into gear, clutch out?

Why would it matter whether transmission is in gear if the clutch is in -- with a traditional manual gearbox (which, I was hoping, the 7MT still is) where clutch presumably sits between the flywheel and the box?
Old 06-13-2016, 02:58 PM
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Originally Posted by LexVan
I do it all the time with a manual trans. Not sure why, but I do.
I keep trying to do this but I've rear ended 4 other cars now.
Old 06-13-2016, 03:02 PM
  #22  
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Originally Posted by Homeles
Open road, 80 mph, hit brakes HARD=No more squeal.
Try not to do this in heavy traffic....
Old 06-13-2016, 05:18 PM
  #23  
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Originally Posted by ...Max...
Wait... do you mean you double-clutch the 991? Or that you clutch in, switch to neutral, rev match, switch into gear, clutch out?

Why would it matter whether transmission is in gear if the clutch is in -- with a traditional manual gearbox (which, I was hoping, the 7MT still is) where clutch presumably sits between the flywheel and the box?
Wow, I'm actually wondering if I've been doing this wrong the whole time. I think what I'm doing is double clutching, but I will describe below. Let me know if I've just been putzing around...

1. When in gear, clutch in and shift to neutral.
2. Rev quickly while in neutral.
3. Clutch back in, put car into lower gear.
Old 06-13-2016, 05:41 PM
  #24  
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Originally Posted by ispool
1. When in gear, clutch in and shift to neutral.
2. Rev quickly while in neutral.
3. Clutch back in, put car into lower gear.
So you're clutching out between 1 and 2? To the best of my limited knowledge that's called double-clutching and my hat is off to you -- I have never learned to do the trick properly (i.e. quickly), assuming that with modern synchronized trannies I wouldn't ever need to...

FWIW I tried to rev-match really obsessively the last few days and still feel the squeak sometimes. Gotta mean "lube me"...
Old 06-13-2016, 06:39 PM
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Originally Posted by ...Max...
So you're clutching out between 1 and 2? To the best of my limited knowledge that's called double-clutching and my hat is off to you -- I have never learned to do the trick properly (i.e. quickly), assuming that with modern synchronized trannies I wouldn't ever need to...

FWIW I tried to rev-match really obsessively the last few days and still feel the squeak sometimes. Gotta mean "lube me"...
Correct. It took some time to learn, and you have to rev a bit higher, but I enjoy the process.

It sounds to me like you have a simple case of a squeaky clutch pedal that needs to be replaced under warranty. My last AMG developed a squeaky gas pedal and they just swapped it for a new one.



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