clutch slurrrr

[grumps]

Hi all took my sg (47k) to westerly exeter today and explained my clutch issues within normal spirited driving and was told the fault is down to a worn clutch ie:87mm of travel as opposed to 350mm when new and out side normal spec i explained about software upgrades(clutch wear recognition) that i have heard about three in 04 but their reply was bmw had not released any up dates! and it was outside of warranty (uac) which i find unfair having only owned the car for 5 months and have covered only 3.5k with only one trip to the ring, any help and advise much appreciated.

[_Nathan_]

Only thing that can really be recommended is to make the massive journey up to see Andy at Murketts as they seem to be the only dealer that actually understands these cars. There have been updates for sure though.

Has it ever had a clutch before? If not then maybe it actually is worn? 47k miles is a fair distance.

PS. 350mm of travel? where is that measured? Not at the clutch I assume?

[Mark CSL]

You could also ask them to take it out and mesure the clutch plate.

If it is below the clutch plate limit you will have to pay but if the clutch plate is over the min thickness they should cover it ok :thumbs:

[shimmy]

Hi all took my sg (47k) to westerly exeter today and explained my clutch issues within normal spirited driving and was told the fault is down to a worn clutch ie:87mm of travel as opposed to 350mm when new and out side normal spec i explained about software upgrades(clutch wear recognition) that i have heard about three in 04 but their reply was bmw had not released any up dates! and it was outside of warranty (uac) which i find unfair having only owned the car for 5 months and have covered only 3.5k with only one trip to the ring, any help and advise much appreciated.

the first thing they will do is reteach it over about 1/2 hour. If you go to Lydney and see Simpsons Motorsport, Ant will do that for next to nothing. All your bitting points will be learnt afresh and updated software loaded up. From Devon this is your best first step.

Then see if anything comes back.

My first clutch was replaced at 42k miles BUT as is wasnt fully worn out it was replaced under BMW good will (no warranty) so i paid half labour which gave me 2 years warranty. second clutch now being done at 67k miles f.o.c under warranty.

[NZ_M3]

There's actually 3 adaptation settings for the SMG clutch alone.

The first is a clutch curve reset (done with the car off)
The second is clutch take up point reset (done with the car off)
the last and most important is the clutch slip reinitialisations (done with the car on)

Personally I think the last re-adaptation makes the biggest difference to the way the clutch behaves (I reset each separately on mine to see what the difference was and it was only on the last re-adaptation that I really noticed a difference). This last re-adaptation change the tolerance given for clutch slip and takes into account wear and the SAC (Self Adjusting Clutch pressure plate) self adjustments.

My clutch is really new however and even that makes a difference to the way it would engage (most noticeable on take off and initial engagement).

I didn't have any slur as such, but did notice a slight slip on intial engagement - it was only upon the last re-adaptation that this cleared completely.

I am making it a habit now to re-adapt the clutch setting on a regular basis and hopefully this will prolong my clutch (theoratically it should) - we shall see!!

[mole]

There's actually 3 adaptation settings for the SMG clutch alone.

The first is a clutch curve reset (done with the car off)
The second is clutch take up point reset (done with the car off)
the last and most important is the clutch slip reinitialisations (done with the car on)

Personally I think the last re-adaptation makes the biggest difference to the way the clutch behaves (I reset each separately on mine to see what the difference was and it was only on the last re-adaptation that I really noticed a difference). This last re-adaptation change the tolerance given for clutch slip and takes into account wear and the SAC (Self Adjusting Clutch pressure plate) self adjustments.

My clutch is really new however and even that makes a difference to the way it would engage (most noticeable on take off and initial engagement).

I didn't have any slur as such, but did notice a slight slip on intial engagement - it was only upon the last re-adaptation that this cleared completely.

I am making it a habit now to re-adapt the clutch setting on a regular basis and hopefully this will prolong my clutch (theoratically it should) - we shall see!!

How do you reset these?

[Thorney]

Take it somewhere else, the amount of times now I get a call about dealers not knowing the CSL is almost at epidemic levels now.

THe only places I personally know have a good idea on CSL's are either Murketts or BMW Battersea.

[Magsy]

Can we have your input here John? Do you get these cars in with the slur and are you able to put it right without a new clutch?

NZ_M3

I've done those resets and teach ins multiple times but it doesn't help, infact sometimes it makes it worse. If there is anything specific about the procedure you know please let us know. (Car hot or cold? I'm starting to think I need to do it stone cold in the morning)

Mole

To do this you need a BMW Diag system (GT1, DIS etc) or a 3rd part tool such as AutoEnginuity.

[_Nathan_]

Take it on a track day and give it loads of abuse, always feel sharper after that IMO.

[shimmy]

well you asked for it so here is my view

ive read it before but i believe there is a problem with the SMG clutches with adjusting the bite points whilst it wears and is being used and abused, probably made worse when it is used hard over time

my first clutch lasted 42k miles but was slipping on and off for the last 10k miles. had a few teach sessions on it and went and away and came back still the same after a while

second clutch had hard use mostly on track but not only and has started to slip now in less than 2 years with 25k miles. I think if it would have been not under warranty i would have put up with it, played with it, made it better but eventually it would have needed changing

Somewhere the mechanics or the software on worn clutches deosnt work properly and it will be a big cost item in these cars if they need changing every 25-40k miles

Just have to keep mine slipping under 2 years! :smt055

[Thorney]

Shimmy is in part right, there is certainly an issue in the interface between the clutch and the software, the problem is that the software is unable to adjust fast enough to allow for mechanical wear that the clutch naturally suffers, this wear also manifests itself in dirt build up etc, basically anything that causes the mechanical interface to differ (wear or lots of time in traffic - essentially the same thing to some extent).

The solution is regular re-calibration, think of it like rebooting your PC, every now and then you do that to clear out memory, IE cache etc etc, the PC doesn't 'need' it per se but it works better after its done. Sadly this re-calibration can only be done with a handful of diagnostic tools, we sue the Autologic (which is by far the most expensive but also the most sophisticated, with upgrades its nearly £15k) or even an older GT1 but these are rapidly getting out of date. BMW continually update the software (I'm not sure if they're trying to fix it or whatever) so you do need things updating.

Only advice I can give is do as we do and make sure every time your CSL goes into a dealer or indy for service is to ensure that the SMG calibration (full not just the bight points) is re-done each time, we include as part of any CSL we see even those in for a quick look over etc, it only takes 20 mins or so, less than that really. The alternative is to rag the crap out of the car regularly, this has the effect of keeping the clutch/flyhweel clean but it wont re-calibrate the software, theres no alternative really.

[Kev.H]

i had mine adjusted made a difference for a while.. seems the harder you drive the better the change :bigcry: i do find if i do a journey switch the car off then back on whilst its still warmed up I get a crisper change ?

[Bounce]

Im off to Murketts next week to get mine sorted,and a couple of other things under warranty.Must be the longest distance for warranty work anybody has travelled.:whistle:St.ives to St.ives[well huntington] 366 miles.;)

[s.mac]

I'll be phoning Andy tomorrow, the software updates have really upset the car :banghead: put your foot down and the dsc kicks in big time ! just no pull and feels like you've knocked the gear stick into neutral :banghead:

[shane@mbtech]

well you asked for it so here is my view

ive read it before but i believe there is a problem with the SMG clutches with adjusting the bite points whilst it wears and is being used and abused, probably made worse when it is used hard over time

my first clutch lasted 42k miles but was slipping on and off for the last 10k miles. had a few teach sessions on it and went and away and came back still the same after a while

second clutch had hard use mostly on track but not only and has started to slip now in less than 2 years with 25k miles. I think if it would have been not under warranty i would have put up with it, played with it, made it better but eventually it would have needed changing

Somewhere the mechanics or the software on worn clutches deosnt work properly and it will be a big cost item in these cars if they need changing every 25-40k miles

Just have to keep mine slipping under 2 years!:smt055

Unless you pay a contribution, which I doubt they will let you, your new clutch will only have warranty until your warranty expires on the clutch they are replacing now. So you wont get 2 years on it I'm afraid shimmy.

[shane@mbtech]

I'll be phoning Andy tomorrow, the software updates have really upset the car :banghead: put your foot down and the dsc kicks in big time ! just no pull and feels like you've knocked the gear stick into neutral :banghead:

try turning traction off;)

[glendog74]

try turning traction off;)

:hahaha: :hahaha:

[shimmy]

Unless you pay a contribution, which I doubt they will let you, your new clutch will only have warranty until your warranty expires on the clutch they are replacing now. So you wont get 2 years on it I'm afraid shimmy.


i can see ill have to try something crafty:thumbs:

[Mark CSL]

i can see ill have to try something crafty:thumbs:
There is the cheeze thing again dont get Daz and Alex started Shimmy :hahaha::hahaha:

[NZ_M3]

Shimmy is in part right, there is certainly an issue in the interface between the clutch and the software, the problem is that the software is unable to adjust fast enough to allow for mechanical wear that the clutch naturally suffers, this wear also manifests itself in dirt build up etc, basically anything that causes the mechanical interface to differ (wear or lots of time in traffic - essentially the same thing to some extent).

I am more on the camp that it has more to do with the SAC (self adjusting clutch pressure plate) rather than the software not accounting for wear to be honest. The normal 6 speed get this on some occassions also - I certainly had it in my 3 pedal 6 speed M3 that was bad enough to warrant the dealer to swap out the clutch - when it came out, it was like new, but the self adjusting clutch mechanism had somehow locked itself and stopped moving.

Here's a possible experiment for somebody - get a pressure plate the same clamping rate as the OEM LuK unit but without the self adjusting mechanism - I wonder if it'll stop all that slurring that's going on!!.

To be honest though, I've only ever experienced the slurring on take off and never on shifting up or down - but then again I never use my car in traffic :supz:


The solution is regular re-calibration, think of it like rebooting your PC, every now and then you do that to clear out memory, IE cache etc etc, the PC doesn't 'need' it per se but it works better after its done. Sadly this re-calibration can only be done with a handful of diagnostic tools, we sue the Autologic (which is by far the most expensive but also the most sophisticated, with upgrades its nearly £15k) or even an older GT1 but these are rapidly getting out of date. BMW continually update the software (I'm not sure if they're trying to fix it or whatever) so you do need things updating.

Couldn't agree more. I am making it a habit of this now with my Autoenginuity tool. It takes no more than 10 minutes or so to reset everything and once it's done, it feels great!!

[s.mac]

try turning traction off;)


Quote:
Originally Posted by lawsy http://www.cslregister.com/forum/images/buttons/viewpost.gif (http://www.cslregister.com/forum/showthread.php?p=45174#post45174)
try turning traction off;)

:hahaha: :hahaha: Yesterday 08:37 PM

:wanker:



:smt044

thats how I get round it :birdman:


:)

[The Gorilla]

Hi,

The ''SAC'' system is as NZ_M3 says at the heart
of a lot of the Clutch issues.

Talk to any spirted E39 M5 Owner and they
will tell you all about clutch slip [Slur].

Put a 850i CSi V12 Clutch pressure plate on a
E39 M5 and you will not have a clutch slur
problem, but you will start ripping out std
rear ARB brackets and Propshaft bearings
for a past time.

The SAC in trying to adjust itself so that the
distance travelled everytime is always the same,
does not function 100 % correctly, never has,
never will, its an inherent design flaw.

It works slighty better on a real Manual Car to a point
but does not like large sharp input loads.

The only two issues with using a uprated Pressure
plate from Sachs etc, is that you have to get into
the habit of keeping it re-calibrated as stated,
and you will start pushing much greater stresses
through the drivetrain.

The 'slur' does in part assist with reducing
drive train load.

Why do you think the E60 M5 came with
the magic 100 BHP sport button.

Most dealers were instructed via BMW to upload
Software changes to the really early SMG Cars as they
were chewing up the Drive train quicker than
BMW could make the replacement parts.

From there on in the cars were supplied from
the factory with the amended and albeit
slower/softer Gearbox software.

SMG is on the whole quite good when its
all working properly, problem is there is
just to much to it, and wear does bring
on functionality issues and problems.

I do not think its possible for a 100% fix for what
was in part flawed from the outset.

Regards,

The Gorilla.

[_Nathan_]

My car had the early software put back on it as it was supposed to be faster.

I've read that you shouldn't use the uprated sachs clutch with a drexler plated diff as the driveline becomes too harsh and starts breaking things - I've got a standard clutch and a plated diff - what setup do you run with your drexler?

[The Gorilla]

Hi,

Nathan- I am currenly running a S50 B32 Dual Mass
Flywheel, with a S50 B32 Pressures plate, and the
S54 Standard Disc.

The S50 B32 Gearbox input shaft is a smaller
diameter, so you use the S54 Disc and
have 2mm skimmed out the flywheel so
the disc is correct distance.

It all seems to work quite well.

I was going to swap out the Dual Mass
Flywheel for a Single Steel one which is about
5kg lighter, so that it does not start
playing around with the SMG, but
allows a little better throttle response,
without getting into 'stall' issues.

The S54 Clutch although the same 240mm
diameter is a different bolt pattern onto the
flywheel.

The S50 B32 std Pressure plate is not
'SAC' and takes around 380/400 bhp comfortably.

Its about 15% less clamping force than the
SACHS uprated one, and about 10 % more
than the S54 'SAC' one.

I did try a 2.5 TD Clutch pressure plate, and
interestingly the Disc in that kit was exactly the same as
the E46 M3 but with a smaller gearbox shaft spline and
thrust bearing.

The 2.5 TD Pressure plate worked fine, but I just
think the S50 B32 is proven.

In the picture, top is S54 Alloy Flywheel,
centre is S54 Dual Mass Flywheel, and
lower one is S50 B32 Dual Mass Flywheel.

Regards,

The Gorilla.

[grumps]

Thank guys for all your help and advise,spoke to dick lovitt (supplying dealer)for warranty or goodwill contribution as very small mileage since purchase five months ago and they basically said sod off ! Bless them.

[glendog74]

spoke to dick lovitt (supplying dealer)for warranty or goodwill contribution as very small mileage since purchase five months ago and they basically said sod off ! Bless them.

How nice - good to see customer support exists there! :banghead:

[NZ_M3]

I was going to swap out the Dual Mass
Flywheel for a Single Steel one which is about
5kg lighter, so that it does not start
playing around with the SMG, but
allows a little better throttle response,
without getting into 'stall' issues.


That'd be mighty harsh on your drivetrain and gearbox components with that setup - you'd basically be running a full solid clutch setup with zero dampening or vibration absorption characteristics.

Interesting what you've managed to mix and match to get working though - worth investigating for sure.

Also what pressure plate's the one on the top right corner of your picture?

[The Gorilla]

Hi,

NZ_M3 - The pressure plate is from a
E39 525 Diesel 1998.

They make about 390/410 Nm of Torque
so it has enough clamping pressure
and fits straight onto a E46 M3 Flywheel
and you can retain the standard clutch
disc.

If and when I change to single mass
steel flywheel, I would use a sprung Hub
clutch disc, but it would not do
much for the loads through the
drivetrain but would assist with
absorbtion/vibration and maybe gearbox
chatter in 1st.

Regards,

The Gorilla.

[SpineOnABap]

The Gorilla - I have a question for you and it's rather technical....


Why are all you posts so 'narrow'? :hahaha: These days most of us use a monitor that can support a full 80 characters across the screen ;)

[NZ_M3]

The Gorilla - I have a question for you and it's rather technical....


Why are all you posts so 'narrow'? :hahaha: These days most of us use a monitor that can support a full 80 characters across the screen ;)


LOL ... at a guess, he's typing his replies out on an iPhone perhaps or similar?