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Just had BMW Ridgefield, CT replace my clutch. It was slipping on hard acceleration at WGI. Wow! Is this how it was when new? It really engages early and I must get used to it! Anyway, should I "break it in" in any way?
 

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M5ROKIT said:
Just had BMW Ridgefield, CT replace my clutch. It was slipping on hard acceleration at WGI. Wow! Is this how it was when new? It really engages early and I must get used to it! Anyway, should I "break it in" in any way?
Just?? ...


A fresh clutch has substantially reduced torque capacity. In my opinion, max capacity is not realized for well over 1000 mi of break-in, unless it's all city stop and go driving. Highway cruising will never break-in a clutch...it requires clutch pedal cycling, stop and go and shifting.

Since the OEM clutch design has marginal capaity to begin with, racing at WOT with under 1000mi is very risky. Sustained slippage on a race track when still "fresh" can result in burning and glazing, so it may never recover.

I would NEVER install an OEM-quality clutch in an M5 expecting to run it on-track. You are asking a lot from a known weak clutch design that is notorious for prematurely failing under modest duty on the street....even behind a 282HP 540i motor.
 

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You may have already broken it in... :hihi: running hard on the new clutch. I burnt mine at under 5K because I did not know how weak the stock clutch was. You shudda gotten a heavy duty clutch......

Good luck guy
 

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Discussion Starter #4
Well I guess 38K and 17+ track days isn't bad for the stock clutch then! It was under warranty if that clarifies anything up. I will definitely have 2K on it before next event at LRP.
What is my option if not going OEM?
 

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M5ROKIT said:
What is my option if not going OEM?
Do a search.... this has been discussed a lot and yes there are options...
 

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M5ROKIT said:
Well I guess 38K and 17+ track days isn't bad for the stock clutch then! It was under warranty if that clarifies anything up. I will definitely have 2K on it before next event at LRP.
What is my option if not going OEM?
You really have three reasonable options for uprated clutch for an M5...

Option 1) Single mass flywheel 11" clutch with uprated premium organic disk.
Option 2) Single mass flywheel 11" clutch with severe duty non-organic disk.
Option 3) Stock flywheel using 9-5/8" aftermarket clutch with severe duty non-organic disk.

Option 1 is more than adequate for most folks. It is good for road racing & very similar to OEM Corvette C5 and C6 setups in both size and design. It is not adequate for some severe drag racing situations where launches involve high RPM & high load, hoping to avoid wheelspin.

Option 2 is the strongest option out there...biggie clutch combined with racey high temp disc material. Hard high friction materials and lack of marcel cushion means engagement will be sudden, compared to organics. Smooth engagement will be difficult, if you're trying to operate in the limo mode. If you want to harness huge aftermarket horsepower or churn tire at will, this is it.

Option 3 is the poor-man's uprated clutch. It does not have much swept area, but the high temp & high friction disk substantially raises torque capacity compared to small organic setups. This small setup can absorb more abuse than stock, but the fragile dual mass flywheel can be fried. It provides marginal modulation & driveability like other racey disk setups.
 

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Per BMW:

BMW AG - TIS
RA: Breaking in SAC clutch
Issue status (03/2002)

Break in the friction linings of the clutch by applying light to medium loads, in the same way as for brake linings. This preconditioning creates a carbon layer between lining and metal friction surface which in the end generates the necessary coefficient of friction. Breaking in can take the form of either normal driving with many gearshifts or a specific breaking-in program on gentle gradients.

"Normal" driving will not damage the clutch. "Normal" driving conditions involve drive-off speeds of up to approx. 2500 rpm on a medium gradient, e.g. when driving onto a transporter. Normal driving off on a level surface at speeds up to approx. 2000 rpm are likewise sufficient.

Sporting driving maneuvers will destroy a new clutch! These include driving maneuvers at high differential speeds, overlaps or very high drive-off speeds, e.g. when driving onto a transporter.

When a vehicle is moved "normally", an empirically established figure of approx. 800-1000 gearshifts is applicable to an optimally broken-in lining.

Please conduct the following breaking-in program in order to avoid later customer complaints:

* specifically for M5 and Z8 vehicles

Breaking-in program for approx. 30 km on road

Vehicle subject to "moderate" shifting processes

Drive off at max. 2000 rpm; upshift 1->2, 2->3, 3->4; upshift at 3500-4000 rpm, downshift 4->3, 3->2, 2->1, downshift at 2000 rpm

Drive off 3 to 5 times on a gentle gradient up to approx. 12%, drive-off speed max. 2000 rpm

:cheers:
 

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XrayMD said:
Per BMW:

BMW AG - TIS
RA: Breaking in SAC clutch
Issue status (03/2002)

Break in the friction linings of the clutch by applying light to medium loads, in the same way as for brake linings. This preconditioning creates a carbon layer between lining and metal friction surface which in the end generates the necessary coefficient of friction. Breaking in can take the form of either normal driving with many gearshifts or a specific breaking-in program on gentle gradients.

"Normal" driving will not damage the clutch. "Normal" driving conditions involve drive-off speeds of up to approx. 2500 rpm on a medium gradient, e.g. when driving onto a transporter. Normal driving off on a level surface at speeds up to approx. 2000 rpm are likewise sufficient.

Sporting driving maneuvers will destroy a new clutch! These include driving maneuvers at high differential speeds, overlaps or very high drive-off speeds, e.g. when driving onto a transporter.

When a vehicle is moved "normally", an empirically established figure of approx. 800-1000 gearshifts is applicable to an optimally broken-in lining.

Please conduct the following breaking-in program in order to avoid later customer complaints:

* specifically for M5 and Z8 vehicles

Breaking-in program for approx. 30 km on road

Vehicle subject to "moderate" shifting processes

Drive off at max. 2000 rpm; upshift 1->2, 2->3, 3->4; upshift at 3500-4000 rpm, downshift 4->3, 3->2, 2->1, downshift at 2000 rpm

Drive off 3 to 5 times on a gentle gradient up to approx. 12%, drive-off speed max. 2000 rpm

:cheers:
Good info, but where do you guys get this stuff? I have always been curious some of you guys seem to always have such technical information handy, About all I am good for is complaining, I personally wouldnt know where to get this stuff, do you find it on the internet or do you guys have freinds that work at dealerships and what not? regardless good info and thanks, Josh
 

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question for Lscman...........

Lscman said:
You really have three reasonable options for uprated clutch for an M5...

Option 1) Single mass flywheel 11" clutch with uprated premium organic disk.
Option 2) Single mass flywheel 11" clutch with severe duty non-organic disk.
Option 3) Stock flywheel using 9-5/8" aftermarket clutch with severe duty non-organic disk.

Option 1 is more than adequate for most folks. It is good for road racing & very similar to OEM Corvette C5 and C6 setups in both size and design. It is not adequate for some severe drag racing situations where launches involve high RPM & high load, hoping to avoid wheelspin.

Option 2 is the strongest option out there...biggie clutch combined with racey high temp disc material. Hard high friction materials and lack of marcel cushion means engagement will be sudden, compared to organics. Smooth engagement will be difficult, if you're trying to operate in the limo mode. If you want to harness huge aftermarket horsepower or churn tire at will, this is it.

Option 3 is the poor-man's uprated clutch. It does not have much swept area, but the high temp & high friction disk substantially raises torque capacity compared to small organic setups. This small setup can absorb more abuse than stock, but the fragile dual mass flywheel can be fried. It provides marginal modulation & driveability like other racey disk setups.
Hi Lscman,
Where can one find/purchase a severe duty non-organic disk ??? Who has the best one? is there a name brand?
Please let me know, okay.
Thank you. :viking:
 

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What I will never understand is: when BMW replaces a clutch under warranty, why can´t the SA spend 60 seconds to explain how to run the new clutch in? Surely, that would save time and money regarding the next clutch. And the next clutch....

The info is there in the TIS, they just have to learn to read it and follow it.

David
 

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XrayMD said:
Per BMW:
...
When a vehicle is moved "normally", an empirically established figure of approx. 800-1000 gearshifts is applicable to an optimally broken-in lining.
...
Now I have to drive to work and count how many time I change gears!!!
:noSMG: 1
:noSMG: 2
:noSMG: 3
:noSMG: 4
:noSMG: 5
:noSMG: 6
:noSMG: ...tell me when i get to 1000!
:M5launch:
 

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Re: question for Lscman...........

FAST 5 said:
Hi Lscman,
Where can one find/purchase a severe duty non-organic disk ??? Who has the best one? is there a name brand?
Please let me know, okay.
Thank you. :viking:
Although a non-organic 9-5/8" clutch has the potential to hold up under M5 power, I have not seen one I trust or want yet. Owners reported Spec clutch out-of-box troubles on this forum 3 times in recent months, so QA/QC stats aren't impressive. Spec is changing their E39 clutch design almost monthly, probably based upon consumer feedback. I see something different every 3 mo. My biggest concern is incomplete clutch disengagement. This has been a recurring theme & this has the potential of warping or damaging $6K tranny synchros. Ignoring these teething issues, I think "grabby", small race puck clutches are a poor substitute for street when civilized, oversize premium organic kits are sold. If somebody releases a more civilized "puck" clutch that disengages when the friggin' clutch pedal is depressed, I might try it (lol).
 

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Josh...

I can't remember where I found this info! Usually, I search this board first, then some other boards, followed by a Google search. Occasionally, I'll get something from the tech or my SA and type that in or scan it in.
:cheers:
 
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