M5 540i V8 V12 Flywheel & Clutch Upgrade

[SRBMW 6]

Hey Guys

E34 540i E39 540i M5 740i 750i 840i 850i M60 M62 M70 M73

As most of you who have a manual V8 BMW, or looking to convert to manual, have found is that the clutches/flywheels in these vehicles are too small, expensive and don't last the distance. So what I've done is develop a flywheel and clutch solution that will:

1. Be alot cheaper to replace and service
2. hold more torque and last longer.

The factory flywheel is a dual mass item, and runs a LUK self adjusting pressure plate. These have a factory clamp load of 2800lb, which isn't too bad, but it only has a 240mm clutch disc. With a fullface clutch disc bigger is better so you will see the photo below of the standard kit and see how much more room is left on the flywheel.

Now most of the time the dual mass flywheels are stuffed and super expensive to replace, so I wanted to develop a kit that had a solid flywheel so that only the clutch kit needs to be replaced and the flywheel can be machined. If you have ever had to replace a BMW you will find they cost alot more than a normal clutch kit so I wanted to use components from another vehicle.

From what I've found there is a couple of suppliers around the world offering upgrade clutches- One of them had a 850i pressure plate and clutch disc,- that's cool if you live in Germany and they are cheap, but here in NZ you would struggle to find one in stock anywhere, and it would be $1200 + just for the clutch. Also these upgrade flywheels are more often than not made of aluminum.

The problem with aluminum is that it isn't a very good heat sink, so they get hot and stay hot and will cause the clutch to slip and get even hotter and eventually the flywheel bends causing endless clutch problems. They can also flex with high clamp pressure plates plus not to mention they are super light which can make a nice car a pain to drive.

So with a bit of kiwi "keep it simple stupid" I've designed a flywheel that uses the non vanos flexplate with trigger wheel, and a flywheel that bolts on over the top. We have to use the non vanos one becuase the vanos one seems to not have a big enough step to locate the flywheel on around the crank.

Then it accepts a Ford V8 10.5" pressure plate. Why? because these are a tried and tested unit that have been operating for around 4 decades and they are relatively cheap, especially in the US where I hope to start selling these kits to. They have around 2800lb clamp factory and have 10.5" clutch disc and alot more surface area. I've had some custom made clutch discs made with the correct BMW spline, the material is a high temp steel backed organic lining with a super strong 6 sprung hub with enclosed springs. Off the shelf HD pressure plates are 3500lb +

The factory flywheel and clutch weigh around 24kgs. With the non vanos flex plate weighing around 4kg this setup is going to be around 3kgs lighter that the factory one. We are starting here so we can see what the the characteristics are like- going too light will change the way the car drives and make it a pig and I want to be able to offer a replacement for stock vehicles.

So we are at a stage where we are going to fit it to one of Rays (Hell Bm) vehicles and we can assess what it all goes like- pedal feel (chatter if any) etc. So the hope is that we can offer an economical,reliable upgrade for V8 and V12 owners.

Will keep you posted.

Edited July 3, 2015 by _Ethrty-Andy_
OP edited to bring down the text wall, nearly died of asphixiation trying to read it

[kiwi535 538]

on the face of it there isnt much difference between 240, and 10.5in = 250+12= 262mm ??

[SRBMW 6]

on the face of it there isnt much difference between 240, and 10.5in = 250+12= 262mm ??

See the pic of the standard 240mm M5 disc and you can see the difference in surface area. The actual width of the facing is much larger and has alot more area. It's the addition of surface area, clamp and material friction that allows it to hold more torque than a stock M5 clutch. Like a Ford or chev V8 with a 10.5 and 11" clutch, it's only a few more mm but the overall increase in diameter helps hold torque. If we supply the kit with a puck disc- the diameter doesn't really make too much difference as the pucks are the same size and it comes down to point loading and friction material.

[Nobimmer 694]

Nice work Darren!

[kiwi328i 118]

Hi,

Is there any further progress with this? I am wanting to do the E34 530i with M60b40 but keep the 5 original speed conversion. I have the uncommon M60b30 manual flywheel that I hope to replace with a single-mass, preferably steel one. I believe the 240mm flywheel is the same or spec'd the same as an E39 540i one. So that's one hurdle. These aftermarket single-mass flywheels are wicked expensive, but the 'fear' of keeping the dual mass is an honest one as my car has done nearly 300k miles and as I am pulling the motor I might as well go the whole hog.

Secondly the clutch kit thereafter, if I use a 328i,528i 2.8 Z3 clutch I would like it to handle the M60b40 grunt. There is a crap load of aftermarket options, but again I could be sold anything as I don't know enough really. Your OP was about looking at a less expensive resolve and one I would like to know more about.

I don't know enough about these things really and I am just an internet troll, but it sounds/looks like you know what you are doing.

If you have any more news that would be awesome

[BM WORLD 1286]

i had a while back a 530i with a 4.4L fitted ,

jb racing ali flywheel (suited the 5spd box) and std clutch to suit

clutch was not upto it at all .

and gearbox chatter was there , if that bothers you.

the clutch that suits as you say is only really a 2.8L to 3L sort of clutch

i could have had it ramped up toi suit , but was to late once it was in there .

was ok i just didn't push it much off the line etc

[kiwi328i 118]

Hi Brent,

That's interesting I remember the car. I might go this way: http://ttvracing.com/?s=bmw#prettyPhoto[iframes]/2/

It's single-mass and steel. its also hell expensive but hey? All solutions over oem are expensive. then I can go with an uprated or std M3 clutch pack and it should be ok. I think I go with sprung hub? I will sort it eventually I guess, but the op of this is also interesting.

Cheers

[SRBMW 6]

Hi,

Is there any further progress with this? I am wanting to do the E34 530i with M60b40 but keep the 5 original speed conversion. I have the uncommon M60b30 manual flywheel that I hope to replace with a single-mass, preferably steel one. I believe the 240mm flywheel is the same or spec'd the same as an E39 540i one. So that's one hurdle. These aftermarket single-mass flywheels are wicked expensive, but the 'fear' of keeping the dual mass is an honest one as my car has done nearly 300k miles and as I am pulling the motor I might as well go the whole hog.

Secondly the clutch kit thereafter, if I use a 328i,528i 2.8 Z3 clutch I would like it to handle the M60b40 grunt. There is a crap load of aftermarket options, but again I could be sold anything as I don't know enough really. Your OP was about looking at a less expensive resolve and one I would like to know more about.

I don't know enough about these things really and I am just an internet troll, but it sounds/looks like you know what you are doing.

If you have any more news that would be awesome

Hi I think I've seen an email come in for this just haven't had a chance to reply to you.

Yes we have fitted one to a 540i with 6 speed and everything seems A-okay. That was with the standard 2800lb cover and HD disc. I'm getting some more flywheels made then I will have a price ready for people. I'm going to have to develop a different setup for the M5 as it seems the trigger is ever so slightly off on the 540 flywheel to the m5 which causes the vanos to not work properly on the m5.

Will be in touch.

[kiwi328i 118]

Awesome.

I will be following this closely. Could be good!

[GTgenie 0]

Hey all

I've had my trans swapped in my '99 e39 540 with an M5 gearbox and the clutch had warn out in a very short period of time. (By HELLBM about Oct-2014)

I've been left hanging with no support from Ray after having immediate issues with the setup. After my initial contact regarding the issue he has closed all communication with me so have been basically trying to get around this on my own. I had come across this forum and signed up hoping this is the setup I was provided as I'm in need of a:

New Clutch Plate to purchase to fit m5 transmission spline

Must be:

- A maximum thickness of 8.5mm (compressed)

- Fit a Ford Falcon Pressure plate as

- Dimension (suspect 265mm will confirm once home)

The car began to exhibit slipping symptoms towards the end of the run-in period (1000km's easy driving high gear) and by 3000kms it wasn't derivable without slipping in 4/5/6th gear so has spent much of this year either parked and eventually sitting in my garage while I was saving money to get it running. I've had 7 Honda vehicles before this all were Manual (type R or Euro R versions) so at least everyone knows I am not a novice driver who burnt out the clutch (as Ray accused me of when I called him for Post work support). The 540i was my first auto vehicle and naturally I wondered how the car would be so much more enjoyable as a Manual so sold my last Honda to pay for the swap.

I have narrowed down my suspected issues to:

1) I suspect my issue to be a hydraulic system issue

2) Clutch pressure plate fork TO clutch release bearing clearance (with transmission closed).

3) Slave Cylinder piston clearance to release bearing fork/leaver

Why:

1) Upon removal of the clutch slave cylinder I noted there had been a decent amount of pressure on the clutch release bearing fork. So as the screws were removed there was decent length of travel with continual pressure. and suspect this to be my primary problem. So I will be putting the unit back together with a new clutch disk and shaving the length of the Piston down.

2/3) Another factor noticed was continual/constant stiff pressure on the clutch pedal all the way from complete lift to full suppression as if the slave cylinder piston was always resting on the forks of the clutch pressure plate. The clutch system was load tested on a machine at Onehunga (sterling brake and clutch) and shown to have no load issues when fully clamped so this does not account for the sever clutch slipping.

The Clutch plate itself would not have contamination issues as the trans housing was fairly clean with no oil seepage inside (with the exception of burnt clutch dust).

I'm currently on the lookout for a clutch disk/plate to replace my one which has been removed (although it has good thickness). I fear my existing plate may have heat spots. Also now that I have the entire transmission and clutch assembly off the vehicle this would be the best time to have this done.

I've been to 5 clutch shops near my area (Onehunga and Manukau region) and managed to get my hands on a replacement pressure plate. I needed a new one as one of the bolts holding this in had rounded and was drilled out and in doing so I damaged the frame of the original pressure plate. Clutch Industries in Onehunga confirmed for me it is a widely used ford pressure plate and had a replacement one for me which I have purchased.

Sterling brakes and clutches also in Onehunga (as with 4 other places visited) were unable to source me a new clutch plate due to:

- The clutch spline diameter and contact pad dimensions did not match anything within their database

Also re-lining the clutch pad was not an option also due to the type of inter plate which was used. Unsure on more detail here but he suggested it may not withstand the forces that will be presented to it if it was re-lined anyway.

Any help in tracking down a replacement clutch plate for this system would be an ABSOLUTE life saver and to anyone who has taken the time to read my post thank you in advance for any advice. I'm literally down to my last few dollars and for what has really been a depressing year for me without being able to drive my 540 if you find me a plate ill pray for your good fortune for your entire life!

I will post pictures soon

Cheers

Michael

Edited July 3, 2015 by GTgenie

[GTgenie 0]

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Edited July 3, 2015 by GTgenie

[will 169]

That flywheel/pressure plate shows definite signs of severe overheating due to slipping. Unfortunately, the degree of overheating visible suggests prolonged abuse/slipping, not generally associated with gentle granny-type driving. If it started having issues on it's own (not because of doing donuts/burnouts etc. ), why did you continue using it instead of parking it and investigating why it was playing up?

I assume this clutch setup is as described by Darren as you have posted it in this topic? If so, the only difference in the setup from that in a V8 ford is that the centre of the friction plate has been replaced with a BMW unit. The overall makeup of the flywheel has no bearing on the matter as the only important issue is that the mating face suits the Ford clutch unit.

Next critical item is getting the release mechanism in the bellhousing to work with the overall flywheel/clutch assembly height. Not exactly rocket science with a conventional clutch assembly.. As this one worked after installation, I would assume that there were no issues here. Post-installation, the only issue I can see occurring is the slave cylinder jamming in a partially active position, causing the bearing to sit in a loaded state on the pressure plate forks. (I do not suspect issues with the master cylinder as this will normally be obvious with a drop of pedal height). This would normally be apparent on removal of the gearbox with the tension springs mating face showing signs of distress, along with the bearing itself having signs of being continuously engaged on its mating face and probably having excessive play due to it not being designed to run continuously at high RPM. In your pic, I am afraid the tension springs' mating face does not show any evidence of prolonged loading. I cannot comment on the state of the bearing without physically examining it. You mention that you found some loading of the bearing on removal, you need to carefully examine the cause of this- simply shortening the push rod might only provide a masking of the actual cause, if this is indeed a fault.

The other items that could cause issues you have described are failure of the friction plate material and collapsing of tension springs in the pressure plate. Your pic of the friction plate shows no visible evidence of material failure that I can see as it looks intact and in reasonable condition, given the degree of slippage you describe. The tension springs in a pressure plate generally fail in one area, leaving visual evidence of a lack of overheating in that area, with the balance showing evidence of extreme overheating due to that lesser area having to do all the clamping work and allowing slippage/overheating as a direct result of not being able to cope. From what I can make out from your pic, the mating surface of the pressure plate shows distress across the whole face, which I would not expect to find in this case. However, a proper examination is needed to properly determine whether the pressure plate did in fact fail. In your case, due to the extended use after failure of the clutch system, I believe this will now be impossible to determine.

Finding a replacement friction plate and pressure plate should not be an issue if the system has been built up from the Ford V8 assembly, all that needs to be done is to have the centre BMW hub installed into the Ford unit. Any competent clutch manufacturing/refurbishing company would be able to do this. This modification would not alter the available clamping pressure of the unit, nor the torque it is able to successfully handle. But before you simply fit it, you would need to get the flywheel checked for trueness/refaced or the whole unhappy saga will just happen again.

Lastly, saying that ownership of several hondas, including some type r models, qualifies you as "not a novice driver who burnt out the clutch" is a bit like saying that you previously designed and built many luxury houses, so it can't be your fault that the first multi-story office block you designed and built, collapsed--- it must be due to materials supplied by others.

Just remember the e39 540i is an ~1800kg blue whale with elephant-like ~440Nm at 3600rpm of torque compared to an integra type R which weighs in at a slim ~1100kg with ~180Nm at 7200rpm of lady-like torque. (The 540i probably has more torque in it's starter motor.. ) 2 totally different vehicles which require driving styles to be totally re-learned when swapping cars for the first time.

Good luck with getting it fixed!

[GTgenie 0]

Thank you Will truly appreciate the feedback.

Below is a picture of my release bearing.

I'm hoping autoclutch may be able to have this done as they advertise custom clutch builds on their website. They weren't open on Saturday so I'll take time out to visit them. So far all other places I've seen have either said try elsewhere or getting this clutch is not possible here.

I understand it is entirely my fault for prolonged use after initial slip being noticed but as mentioned I pointed it out the very first time it was noticed to Hellbm. It's just my circumstances that left me to be forced to keep driving it knowing I'd be going about this on my own. I drove it once to maraitai beach and it got home fine without slipping symptoms but the very next day after a cold start it was slipping enough to be noticed.

So in an effort to fix this since new years I saved for and purchased:

- firstly a spare car while bmw would be out of commission

- a LUK factory m5 clutch kit

- etorx and torx head socket sets to remove transmission/ clutch

- rear main crankshaft seal and gasket

- valve cover gaskets

As mentioned I eagerly purchased an OEM m5 clutch kit for the m5 trans little did I know there was no hope of using it till I had everything out. Problem with using this I'd the one local dual mass flywheel too my vehicle is $1300. Is there such a thing as a good used dual mass flywheel?

As its OEM the friction plate can't be used with a solid flywheel as it has no damper Springs. (too much shock potential for mounts, trans, crankshaft braking)

Lastly my intention with mention to driving previous cars/track days was just that they are high reving and very responsive motors which taught me to be graceful with gear changes to reduce shock and not abuse your transmission, engine mounts etc. Always Rev matched gear changes and under braking.

I really to have a new found appreciation for v8's after my first Drive in the 540i as an auto. Torque is like nothing I had driven before especially from the low rev band. This was also why I purchased the 540i for its NA motor and that immediate throttle response you don't get with a turbo.

Like most on this forum I enjoy driving and maintaining my own cars to be able to drive the beautiful rural roads NZ has.

I definitely have a thing or 2 to learn about v8 engines and I'm open to all advice. I just really want to get the transmission bolted up right this time. This forum and all its members of like minded individuals seemed like the perfect place :-)

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[GTgenie 0]

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[B.M.W Ltd 950]

My opinion would be that the release bearing has been loaded full time with the pressure plate fingers with no unloading and preplay

Edited July 5, 2015 by B.M.W Ltd

[westy 614]

The spring in the slave keeps the release bearing is in continuous contact with the fingers of the pressure cover. Unless it's bottomed out in the slave? Would be a bit odd given the big depth of the dual-mass though.

For what it's worth I've never received a warranty on modified/specifically built parts so...

[B.M.W Ltd 950]

The spring in the slave keeps the release bearing is in continuous contact with the fingers of the pressure cover. Unless it's bottomed out in the slave? Would be a bit odd given the big depth of the dual-mass though.

For what it's worth I've never received a warranty on modified/specifically built parts so...

Correct... In contact... not loaded, that's why I said loaded. The release bearing in the photo looks like it has been under constant load against the pressure plate fingers. I"m wondering whether there is a difference with some of the release bearing carrier heights like there is with the 6 cylinder clutch set ups. I've not done an "8". Easy to measure up to come to the right conclusion though.

Edited July 5, 2015 by B.M.W Ltd

[will 169]

That release bearing is showing definite signs of running hard up against the pressure plate tension springs! Are the visible 'dash' marks actual indentations ? If they are, then your pressure plate would have been semi-loaded and not providing the grip it was supposed to.

You definitely need to check clearances between the bearing/pressure plate, firstly without installing the hydraulic slave cylinder, to ensure there is good mechanical clearance. If this checks out, install the slave cylinder/pushrod with its piston in the fully retracted position (with cylinder empty of fluid-not connected to the hydraulic system) and make sure it does not load up the bearing onto the pressure plate springs- there MUST still be good mechanical clearance to allow for wear of the friction plate which will naturally lift the spring height and close the gap.. Once all is checked and OK, the hydraulic system can be filled, bled and clearances checked again.

BTW, all the measuring can be done with the gearbox on the bench if you make a suitable jig to mount the flywheel/clutch assembly to the 'box.

IIRC, the OEM M5 clutch setup has to be used with a dual mass flywheel as it adjusts itself in conjunction with the dual mass system..? Could be mistaken but remember this being discussed on one of the overseas forums where there are plenty of M5 V8 bm's around and plenty of blokes trying out all sorts of things.

Large delay in replying as I have been in and out all day trying to get my tractor going in amongst the almost continuous rainstorms so I can finish off drilling holes for fence posts.... damn diesel injector pump..

Second-hand dual mass flywheels can be reused but you need to carefully examine them before committing to using them. They are always a risk, but if $$$ is an immediate issue, and you are prepared to haul the whole setup down at some later time, then it is worth the risk, especially if the alternative is walking...

[BreakMyWindow 1878]

Fyi you can buy a genuine M5 clutch and flywheel for around 1100nzd ex oseas. That includes shipping and taxes.

[polley 916]

Fyi you can buy a genuine M5 clutch and flywheel for around 1100nzd ex oseas. That includes shipping and taxes.

How long ago was that? The conversion rate is pretty sh*t right now

[BreakMyWindow 1878]

Good point.

2 months ago.

[GTgenie 0]

Thanks for all the feedback guys I'll be visiting autoclutch this Friday who said the custom ford clutch plate with a bmw center spline will be no problem for them. Once I have the new in and assembled I'll take some measurements.

Another thing to note the release bearing that came out does not pivot where as the OEM one which came with the clutch kit does. I wonder if this uneven initial pressure on the pressure plate Forks could be a contributing factor also. It is slightly longer in sleve length so I have some options now for making additional space inside the bellhousing once it's all bolted back up.

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[will 169]

Do you have decent pics of the release bearing/lever/pivot setup you can post up here/PM to me?

Edited July 7, 2015 by will

[Allanw 1072]

This isn't the only car to have this exact same issue.

[will 169]

This isn't the only car to have this exact same issue.

Please enlighten me.. PM if you dont want to say anything on the open forum.