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Discussion Starter #1
Hello all,

I am the new proud of a '00 cblk/blk w/ 32k miles and a UUC short shift (I don't know if this matters), and have noticed a strange tendency when shifting quickly under hard accelleration (keeping the gas pedal to the floor and quickly depressing and releasing the clutch, and slamming to the higher gear in between the clutch action).

What happens is the rpm's rise rapidly when the clutch is released, and it feels like there is some hookup (forward propulsion), but not completely engaged. It isn't until you come off the throttle a bit that you feel the car 'hook up'.

Is this a slipping clutch, or is this a safety feature that is preventing me from doing harm to my car? If it is a clutch, does it sound like it needs replacing? The car has no other clutch issues doing anything else anywhere.

Thanks for the help.

Brian
 

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What you've discovered is your M5 has an undersized clutch & it's getting scorched. It happens to the 400HP M5 and it also happens to it's sibling 280 HP 540i V8. The M5 clutch is a tiny 9-5/8" (same as other BMW 4 & 6 cyl cars), while most powerful V8 cars come with 10.5" thru 11" clutches. It simply does not have enough surface area to absorb the heat or transfer the torque. Some folks have replaced the original clutch 3 times!!

The permanent, durable solution is to install a UUC 11" oversize clutch assembly. It is not cheap, but it will make the tires bark at will...like other 11" clutches.

Search for UUC on this forum. Several vendors sell it.
 

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Yep, your clutch is slipping. But I highly reccomend that you do not hold the car to the boards when upshifting. The car is not an American muscle car and damage will be done to it if you continue to do that. The M5 is pretty tempermental about its clutch and most members have found that the best way to upshift is the general off the throttle and then back on method. Hope this helps.
 

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Discussion Starter #4
Thanks TC and Lscman. My fears confirmed. I guess I'll take it easy while I do some shopping.

Brian
00 carbon black
 

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Unfortunately, say bye bye to your clutch. I had the same issue and had the clutch replaced under warranty. 32K on my '01. Is your M5 CPO'd? If so, try having your clutch replaced under warranty. I second Lscman's recommendation if I had to pay for a clutch replacement.
 

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I had my clutch replaced 6 months ago by BMW, and they said it has a 2 year warranty. Will they still replace it for me under warranty?
 

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I bought my M5 new in 2000; it has 45k miles and every once in awhile the clutch will slip, but never under what I would consider normal circumstances.

For instance, I was in 6th gear on a two lane road the other day and had not touched the clutch in about 1/2 hour. I had been driving the car in a civilized manner for about an hour. I went to downshift to fifth to pass, and the clutch took about 2 seconds to engage after my foot was off the pedal. There was not a lot of power involved, and the rpm diff between 5th and 6th is pretty small.

But the clutch has never slipped when you would expect it to - like doing quick starts, power shifting, climbing a hill in a gear or two too high.

It has done this about 10 times since new. The dealer could never duplicate it and for that matter neither have I been able to intentionally repeat it. I have just considered it an anomaly and am in no hurry to replace the clutch since it works correctly 99.9% of the time. But when I do replace it, I will go for a much bigger unit.

Steve
00 M5
99 996
 

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I bought an E39 M5 yesterday from a BMW dealer in England (first registered August 2000, 46,000 miles). I'm the smooth type - don't believe in driving hard a car that does not belong to you, or one you do not yet know.

I did try one full-bore change from 2nd to 3rd on the test drive, once the car was properly warm. Guess what? The clutch slipped for at least a second or a second and a half.

Waiting to see if they replace the clutch before I take delivery on Wednesday.
 

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Replace it or not, you will still have a factory clutch that WILL slip during hard shifts. My '00 had 26k when I bought it (6-mts ago), and the clutch would slip. I had the clutch & flywheel warrantied-out, and after only 4k miles the new one would slip too (during hard shifts!).

If youa re going to "drive it like you own it" :wroom: you may want to look at getting the UUC Clutch.

Robert

Timray said:
I bought an E39 M5 yesterday from a BMW dealer in England (first registered August 2000, 46,000 miles). I'm the smooth type - don't believe in driving hard a car that does not belong to you, or one you do not yet know.

I did try one full-bore change from 2nd to 3rd on the test drive, once the car was properly warm. Guess what? The clutch slipped for at least a second or a second and a half.

Waiting to see if they replace the clutch before I take delivery on Wednesday.
 

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Timray said:
I did try one full-bore change from 2nd to 3rd on the test drive, once the car was properly warm. Guess what? The clutch slipped for at least a second or a second and a half.


AAAaaaaaaaahhhhhhh!

Yes, the clutch will slip. But YOU LET IT SLIP! For a second and a half? Shame on you! If you had simply recognized what was going on and lifted for a tiny moment it would have hooked up. When you let a clutch slip under full throttle like that, you will burn it up.

I'm not trying to pick on you personally, but everyone needs to know the following:

1) Clutches are designed to transmit full torque when they are locked up. NO CLUTCH will last long if you transmit 400 ft-lbs through it while it is slipping. Some clutches make this easier or harder to do - the M5's clutch most definitely puts more responsibility on the driver.

2) The M5 clutch CAN and often does last a long, long time - even under performance driving conditions. The difference is driver skill. And I acknowledge that there is no way to extract that absolute most performance out of the car in a drag race without the driver ALLOWING clutch clip under power. I have 75K miles on my car. The clutch was replaced under warranty about about 35K only because of a malfunctioning auto-adjust mechanism. The second one is still very strong.

3) For our newer members who actually don't WANT to have to replace their clutch prematurely, or spend thousands on an aftermarket upgrade, I give you Virtual M5 Driving School - which demonstrates normal and high-performance techniques that perserve the clutch.
 

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greg said:
AAAaaaaaaaahhhhhhh!

Yes, the clutch will slip. But YOU LET IT SLIP! For a second and a half? Shame on you! If you had simply recognized what was going on and lifted for a tiny moment it would have hooked up. When you let a clutch slip under full throttle like that, you will burn it up.

I'm not trying to pick on you personally, but everyone needs to know the following:

1) Clutches are designed to transmit full torque when they are locked up. NO CLUTCH will last long if you transmit 400 ft-lbs through it while it is slipping. Some clutches make this easier or harder to do - the M5's clutch most definitely puts more responsibility on the driver.

2) The M5 clutch CAN and often does last a long, long time - even under performance driving conditions. The difference is driver skill. And I acknowledge that there is no way to extract that absolute most performance out of the car in a drag race without the driver ALLOWING clutch clip under power. I have 75K miles on my car. The clutch was replaced under warranty about about 35K only because of a malfunctioning auto-adjust mechanism. The second one is still very strong.

3) For our newer members who actually don't WANT to have to replace their clutch prematurely, or spend thousands on an aftermarket upgrade, I give you Virtual M5 Driving School - which demonstrates normal and high-performance techniques that perserve the clutch.
:M5launch:
 

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Thanks, Greg, very interesting. I'm pleased to realise I have a lot to learn -- the idea that M5 ownership might make me a better driver is much more satisfying than to see this as a flaw in the car (on which I shall keep an open mind, given other posts).
 

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Great information. My 2000 has 60K and seems to shift just fine.



greg said:
AAAaaaaaaaahhhhhhh!

Yes, the clutch will slip. But YOU LET IT SLIP! For a second and a half? Shame on you! If you had simply recognized what was going on and lifted for a tiny moment it would have hooked up. When you let a clutch slip under full throttle like that, you will burn it up.

I'm not trying to pick on you personally, but everyone needs to know the following:

1) Clutches are designed to transmit full torque when they are locked up. NO CLUTCH will last long if you transmit 400 ft-lbs through it while it is slipping. Some clutches make this easier or harder to do - the M5's clutch most definitely puts more responsibility on the driver.

2) The M5 clutch CAN and often does last a long, long time - even under performance driving conditions. The difference is driver skill. And I acknowledge that there is no way to extract that absolute most performance out of the car in a drag race without the driver ALLOWING clutch clip under power. I have 75K miles on my car. The clutch was replaced under warranty about about 35K only because of a malfunctioning auto-adjust mechanism. The second one is still very strong.

3) For our newer members who actually don't WANT to have to replace their clutch prematurely, or spend thousands on an aftermarket upgrade, I give you Virtual M5 Driving School - which demonstrates normal and high-performance techniques that perserve the clutch.
 

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greg said:
AAAaaaaaaaahhhhhhh!

Yes, the clutch will slip. But YOU LET IT SLIP! For a second and a half? Shame on you! If you had simply recognized what was going on and lifted for a tiny moment it would have hooked up. When you let a clutch slip under full throttle like that, you will burn it up.
Greg,

The driver is hardly at fault. We're not talking full throttle powershifts here!! Drivers are lifting when the clutch is depressed and immediately applying full throttle as the clutch pedal is released. This is how I've accelerated with manual transmission cars since 1972 (about a dozen cars or more)...and I've never had a problem with slippage on upshift until I bought a 282 HP E39. This seemed odd to me, until I saw the problem was widespread (lol). The granny shifting-clutching-throttle method you recommend to "protect" or otherwise baby the marginal clutch will result in 14 flat 1/4 mi times, no better. Go to the drag strip and try it...see your timeslip! You will easily give up 3/4 second or more in the 1/4 mi compared to somebody ripping off upshifts without babying the clutch. How much sense does that make when folks are installing $8K headers to gain about 0.3 sec? I have compared both clutching/shifting methods while piloting many vehicles at the drag strip. You are not taking advantage of the stored kinetic energy in the flywheel and ANY delay in throttle re-application is lost thrust. You need to apply full throttle IMMEDIATELY or you're losing time. A clutch of proper size is expected to grip without protest. An aggressively-driven E39 540i with a strong clutch that makes the tires bark will clean your clock, if you're using no throttle during shift overlap. I learned this long ago running cars at drag strips. A passive shifting method turns the M5 into a toothless beast, except for single gear roll-on speed burst contests.
 

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No more difficult than changing-out to an OEM Clutch/Flywheel. I no longer have to "baby" shift, I can shift HARD and fast.....NOOOO SLIPAGE! Here is a link to my review of the UUC Clutch/Flywheel upgrade here
Robert
MEnthusiast said:
How difficult is the UUC upgrade?
 

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Robert,
Thank you. I think I baby the car so Im not too worried, but when/if I need to change the clutch I might as well do this upgrade.
 

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I might also add that the grannyshift method (clutch out, wait, apply throttle)being recommended by Greg is precisely what I was obligated do at Watkins Glen and Beaverun this summer/fall. My stock clutch slowly degraded (from severe duty use) and was not engaging crisply anymore. The symptom was my tach "hung" on upshifts for a good 1-1/2 to 2 sec before engaging. My exhaust is too quiet to hear the engine pitch with the windows open, so the problem kinda snuck up on me. Using these clutch-conserving throttle delay methods at the tail-end of these events, my lap times went up by about 2 seconds per lap!!! Two seconds is almost the difference between race and street rubber....keeping in mind my lap times usually continue to drop thru the last session.

I could run track time "forever", using a conservative shift overlap technique and I'm sure my clutch & flywheel appreciates it. I will say the clutch rejuvenated some after each track event, but frankly the organic lining is cooked to a crisp & damage not reverseable. Slippage will quickly occur with any brief flogging. In fact, in a straight line standing start, I can't even break my tires loose in first gear anymore with race rubber. The car accelerates almost like I have a high stall converter with an automatic. With street rubber installed, the tires will literally churn in first and it will chirp 2nd and 3rd gear.

This is life with an OEM clutch. I find it unacceptable to baby the clutch and compromise performance.
 
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