very stiff clutch - The Unofficial BMW M5 Messageboard (m5board.com)

DP400 · 9th January 2007, 16:18

Hi all,

First dumb question from a new owner coming up:

I know the early 3.6's have a much stiffer clutch than the 3.8's and using the car on the journey to / from work in traffic is a bit of a pain.

Ive been told that its not the actual clutch that makes the 3.8 easier, but the clutch master cylinder. Can anyone confirm if this is correct and if so can I change mine to the 3.8 version and who in the North London vicinity could do it and how much would it be likely to cost?

Told you it was a dumb quesiton, i look forward to being corrected if I've got it all wrong.

dronfieldm · 9th January 2007, 18:35

I am sure other members will be able to provide a more helpful reply, as some may have tried the clutch swap already.....

The only mention I can see in the BMW Press Pack for the 3.8's launch is "a special clutch with modified diaphragm spring"......

mblaster · 10th January 2007, 01:39

The clutch started getting real heavy when mine was going out. The new one is quite light.

davidoli · 10th January 2007, 10:34

The clutch on my 3.6 is very heavy , although I like it ........pity my left thigh muscle doesn't fit into my jeans anymore though !

milesr3 · 10th January 2007, 11:20

It was me that told Dave that the clutch pedal weight was lightened around 92, but I don't know whether this was referring to the 3.8 introduction or some change to the 3.6. I remember reading it somewhere, but I can't find it now. I thought this was with a different ratio of master and slave cylinder rather than the spring plate, which presumebly is going to be at least as strong with the 3.8 given it has more torque?

Or was I wrong and the 3.8 has a different clutch too, which is much lighter. I know it has a different (dual mass) flywheel.

I done some searching and read the FAQ and wiki too and can't find it there. Anyone know this?

Richard

farrell · 10th January 2007, 11:22

Hi
Richards on the right line.
The original clutch was stiffer on the 3.6
They changed the cover plate stiffness (less) & friction face material on replacement service clutch kits to try & maintain a similar clamp load.
The 3.8 has a different slave cylinder & release arm.
The combination of greater hydraulic displacement & greater mechanical leverage of the release arm served to reduce mechanical effort at the foot pedal.

I think the clutches are were different but will confirm.

Farrell

davidoli · 10th January 2007, 11:47

I had a new genuine clutch fitted to my 3.8 and it is remarkably light......If I jump out of the 3.6 and get straight into the 3.8 it's almost as if there is no clutch weight / resistance at all !

I love the heavy / race clutch type feel of the 3.6 though !

dronfieldm · 10th January 2007, 12:21

I get the distinct feeling you aren't going to be able to swap one for the other easily.

I'm also sure the clutch weight changed when the 3.8 was introduced, as others have indicated.........

I've never driven a 3.6 so don't know whether its a lot heavier than the 3.8, but from what Davidoli says, it is.......

Mark

davidoli · 10th January 2007, 12:47

I wouldn't listen to him if I was you .....he talks rubbish !

farrell · 10th January 2007, 12:54

3.6
01 SET RMFD-CLUTCH PARTS ASBESTOS-FREE D=240MM 1 21212226428
02 RMFD CLUTCH DISK ASBESTOS-FREE D=240MM 1 21212226593
03 CLUTCH RELEASE BEARING H=25MM 1 21512226729

3.8
01 SET RMFD-CLUTCH PARTS TWIN MASS FLYWHEEL D=240MM 1 21212227246
02 RMFD CLUTCH DISK F.TWIN MASS FLYWHEEL D=240MM 1 21212226958
03 CLUTCH RELEASE BEARING H=25MM 1 21512226729

Only the release brg is is the same.

Twin mass flywheel was always going to make a difference despite the clamp force release pressure effort between the 3.6 & 3.8.

Farrell