M series cable clutch improvement

[NicBowman]

Hi. I have put this on FB, but PH is a better permanent record.

My 3000S clutch is very heavy and the clutch action is very high. To lower the force I simply drilled another hole in the pedal arm, at the cable attachment. The new hole is lower, closer to the pivot. This improves the gearing, effectively the cable gets pulled less far, so less work done and lower pedal force. I went 10mm down, giving 15% reduction in force, you could go 15mm down and still be okay.

Pics tell the story. 10 min diy job. Feels much better.

Nic

[NicBowman]

Let me add. The cable tension is defined from the gearbox end. The load to depress the clutch fingers divided by the release arm ratio gives the cable load. The pedal box end has no effect on the cable load. If I could adjust the gearing at the gearbox end it would be better, but not looked yet.

The clutch pedal modification merely reduces the pedal force, hence the clutch pedal pivot load. So should in theory not increase the risk of cable breakage, but should lower the wear at the clutch pedal. Plus make life more pleasant!

It also decreases the throw of the clutch mechanism, moving the bite point a bit lower.


If anyone has done this before and had bad results please post.

Thx

Nic

[NicBowman]

Hi.

I have a huge respect for Adrian, both personally and professionally, plus he is 'the man' with respect to M series (and others). So not going to contradict.

But, technically it makes sense, it just adjusts the ratio (as in later pedal boxes), it also doesn’t change the cable load.

So, if you are struggling with pedal loads, try it, but if you listen to Adrian, carry a spare cable!

Mine feels much better.

Best


Nic

[Adrian@]

Nic, I deleted my post ...thinking about it now...this will be the thing to do on FB, rather than look at the basic issues that revolve around a stiff clutch. I will leave you with it. A@

[NicBowman]

Hi. It is also worth mentioning that the original cable routing is psychopathic. It needs a bracket on the front of the sump then to trail through the wheel arch, below the steering. Make a new hole in the wheel arch. Will add photos. Sure this is all well known.

Nic

Edited by NicBowman on Saturday 26th August 22:47

[NicBowman]

[plasticpig1972]

Thanks Nic,
good info. On my 3000M the previous owner fitted a heavy duty clutch for some weird reason i don't understand. This means the clutch pedal is sooo heavy it's crazy and put's more strain on the cable.
I'll drill asecond hole nothing to lose.
Later in the year i will take the engine out and fit a standard clutch assembly to make the car nicer to drive.
my 3000M has a standard engine so no need at all for heavy duty clutch.
Cheers
Alan