Le Mans

I have had my 01 m5 recently in for a new clutch when it started to slip at 1350 miles. 400 miles later the clutch feels like it is slipping again. Here are the symtoms;

1. Engine revs up but car does not seem to accelerate as fast as it was when i forst got the car. (car still does accelrate but it no longer has that kick)
2. Car is hardly able to engine brake (I put the car in second gear to slow down and the car does not slow down the car half as well as it used to)
3. Virtually impoosible to produce wheel spin between first and second gear change. ( used to do it quite easily before clutch probelms)
4. Cannot go past 40mph from standtill in first gear. (Easily did this before clutch probelms)

I took the car back to my dealer and the shop foreman drove the car with me and he says everyhing seemed fine. What should i do. I strongly feel that the clutch is slipping.

Thanks for any help

ivory1

Make sure you have written documentation that after the reported clutch repair, the problem is not cured. Keep a log of your phone calls and discussions with the shop -- record names, dates and times. Perhaps no repair was performed on your vehicle at 1350 miles and the problem has only gotten worse. Do you prefer to drive with DSC on or off?

Jacob Lee

with the strongest emphasis possible - this is not a flame nor attempt to be sarcastic, just a question to discover facts that may help those who've already had or are dreading that they may one day also have clutch slippage problems:

1. i currently have 6200 miles and my clutch feels just the same today as the first day i got my M5. However, I have:
a) never downshifted into a lower gear such that the tac would be higher than 3500-4000 or so.
b) never spun my wheels
c) never gone higher than about 5k off first gear, and even then, rarely so. 90%+ of the time usually shift off first around 3-4k.
d) never redlined in any gear
e) never went anywhere near 40mph off first gear

In other words, I punch it in higher gears now and again, and drive on occasion in a spirited manner through the twisties, but not enough to do any of the above.

Perhaps it would help to determine if the clutch is defective in some true mechanical manner, or rather just understrength by design for the abilities of our brutish M5s (at least based on experiences here)

So, to eliminate the obvious as it would only take one true yes answer, please think carefully and realize you affect us all with an incorrect reply:

Q: Is there anyone here who HAS had their clutch start to or already slip, but who has also never done any of the above things in the list above?

Again, this isn't a comment or objection to how anyone chooses to drive their M5. I just want to know if I might be able to just avoid the clutch problem if I continue to drive the way I do.

If the clutch slippage problem so many of us have reported here is due to being an understrength/underdesigned clutch for the full power of the M5, then there should be lots of people like me who hasn't seen any sign of it, and even those in their 20-50k range who also hasn't seen a sign of it. And perhaps never see it.

If it has nothing at all to do with driving style but is a defect, then like any other defect it should just be a straight stastical percentage. Except for some very few glaring exceptions, no "defect" is truly 100% across the board, although everyone is of course legally entitled to a recall. So if it's a defect, there should be people who have babied their M5s from day 1 but had clutch slippage from as early as day1 to whenever, and people who've floored it and done every single thing on the list above that I haven't done and yet still have a perfect clutch.

I'm actually hoping there are at least a couple people who drive just like me but who have or already had clutch problems (therefore invalidating the understrength theory - unless we're saying it's SO understrength that even babying the M5 gets the same problem ). It would actually make me feel better to know all I have to do is replace my clutch with a stronger clutch so that I can push my M5 without feeling like I'm going to give myself clutch slippage, than to have this dread in the back of mind that it could just "happen" whenever.

Le Mans

I am testing all this with DSC off and sport button on. The car barely reaches 60mph at second gear. I have not driven the car hard at all. the current clutch slippage is relatively minor compared to before, but it is defently huring the performance of the straight line acceleration.
Please help. Are there any other things that indicate slippage other than burning odor?

kgk

If I am not mistaken, this is the rule of thumb:

=> Clutch damage can only happen when the pedal is pressed down to some limited degree (is above friction point but not totally up), and the speeds on the two sides of the plates (engine vs. transmission) are different.

So, if you have the pedal up, #b, #c, #d, and #e should not matter.

I'm suspecting that the kinds of things that wreck the clutch are:

1. letting a foot rest on the pedal (keeping it slightly pressed)
2. not matching the RPM's on the upshift or downshift very well
3. keeping the pedal down for things like long launches from N->1st

and, of course,

4. defect in manufacture or design.

The first two are operator error, #3 is crazy fun, and #4 is BMW's fault.

Think of a clutch as two pieces of material that are pressed together by springs. When they are tightly pressed, they will not slip. When you're letting the pedal up (coupling) or down (decoupling) is when the wear must take place.

I'm not a mechanic, but this seems obvious when I wear my physicist hat. I'm sure that I'll be corrected by a real mechanic before long!

So, in summary, many M5 clutches are fried by sheer abuse (and you guys RULE), some are fried because people just don't know how to shift gears, and some are fried because BMW might not be doing a very good job on their hardware. If I'm not mistaken, production is stopped this month while they work on clutches, if I am not mistaken....

Jacob Lee

by my definition, trying to reach 60mph in 2nd gear is driving the car hard.

again though - strong emphasis - i think we all ought to be able to drive our cars to the limit of it's design. if they're going to give us such a fantastic engine and suspension system, we shouldn't be saddled with a weak clutch. i'm just so paranoid now since i knew all about this clutch problem before getting my M5 that i've babied it since day1 in what i hope is not a vain attempt at staving off getting the problem.

i'd love to be open my car up more, but because of this uncertainty, i've settled for moderate driving, not really aggressive. i just want to be able to verify that it is an underdesigned clutch; which if it is, I can therefore greatly increase my chances of avoiding seeing a problem by continuing to drive the way I do.

Jacob Lee

kgk,

well, you've sold me at least on the points about b,c, and d
makes sense from a physics point.

i was practically gnawing my own liver out with frustration in not being able to really play with this beautiful new toy that i knew was way past the 3100 mile break-in point and therefore safe to floor and go past 5k.

that was my rule - i NEVER went above 5k on the tac for any reason in lower gears, and never above 4k in the 4-6 gears. FRUSTRATED doesn't even begin to describe my angst.

it's like - some genie pops in, snaps his fingers and says - here you go, the most beautiful woman on the planet is yours to command. but if you have sex with her, you'll die young. real young.

argh! oh well, i'm going out on hwy 280 right now and having some FUN

kgk

Yes! The [clutch] pedal is up and you see a delay between the speedometer and the tachometer movement. This will be most obvious under load (when you are accelerating, etc.).

There could be more, but I'm not sure.

[This message has been edited by kgk (edited 24 May 2001).]

blue max

fais2000 where are you?

IMHO the clutch problem so many are having is the result of a design flaw.

1) How do you explain that seasoned drivers with other BMW's, M3's, M roadsters & M Coupes have had zero problems well past the 40k mile mark? My last car made it to 80k on the original clutch.

2) Right now there are 2 camps. Those with clutch problems & those with pending clutch problems.

Why are some being replaced under warranty others not?

Parkerfe

I think JacobLees points are valid food for thought. Although my clutch was repalced at around 12,000 miles(under warranty), I have to admit is was probably my fault. I would often drop the clutch and spin the tires through first and second gears just for fun ! That's not good for any clutch. If fact, i first noticed slippage and smell after such a burn out. I suspect that if one drove the M5 like they do most other cars there would be few clutch problems out there.