Heavy Clutch

[GreatOldOne]

I'll have another play when I get back from work, and report back.

[MartinClan]

Iteresting thread this. I thought I would just have my 5 peneth worth :-)

Ultimately, to reduce the pedal effort without using something fancy like BMW spring assistor, there are only two things you can do.

1. Reduce the friction in the system. I think all that can be done here is to make sure everything lines up OK.

2. Change the leverage so that the pedal has more travel

I have the standard Marlin setup except that I braced the top of the bulkhead to reduce the flexing of the pedal box. The clutch and brake pedals are both at the same level at rest and the clutch pedal travels pretty much all the way to the floor. I think if you increase the travel on the clutch pedal it will be higher than the brake pedal - which is not very desirable. I suppose you could always change that as well....

But - is it all worth the effort? I found the pedal hard work to start with (after driving a modern tin box) but I soon got used to it (just call me Arni...) And I guess most of us won't be doing long journeys, where fatigue is a factor, very often.

Robin

[Mike]

Originally Posted by MartinClan

Iteresting thread this. I thought I would just have my 5 peneth worth :-)

Ultimately, to reduce the pedal effort without using something fancy like BMW spring assistor, there are only two things you can do.

1. Reduce the friction in the system. I think all that can be done here is to make sure everything lines up OK.

2. Change the leverage so that the pedal has more travel

I have the standard Marlin setup except that I braced the top of the bulkhead to reduce the flexing of the pedal box. The clutch and brake pedals are both at the same level at rest and the clutch pedal travels pretty much all the way to the floor. I think if you increase the travel on the clutch pedal it will be higher than the brake pedal - which is not very desirable. I suppose you could always change that as well....

But - is it all worth the effort? I found the pedal hard work to start with (after driving a modern tin box) but I soon got used to it (just call me Arni...) And I guess most of us won't be doing long journeys, where fatigue is a factor, very often.

Robin

Robin
You are absolutely right.
I made new pedals, with proper needle roller bearings to reduce friction as much as possible, as I did not like the standard Marlin brass bushes. I have to say though, this will have only made a marginal difference to the friction.

My clutch pedal was level with the brake pedal (I checked my Audi and it is 10-15mm higher than the brake pedal - and I had never noticed!) My clutch pedal the travel was only half way to the floor. I have now stripped it all out and will use the lower hole of the two supplied by Marlin - at 55mm centre from pivot, compared to 80mm centre originally used. This has increased the travel significantly, and will, as you say, reduce the effort to the same extent. A spin off is the plunger rod to the master cylinder now moves through a smaller arc and stays much more in line with the master cylinder than it did previously.
I have also spent the evening making a 'helper spring' bracket as I am not doing this all again!!
Mike
I shall be interested to see how Jason gets on with his experiment.

[GreatOldOne]

The experiment was (In my mind) a complete success.

I made the angle of the master cylinder shallower by stacking some washers under the lower box section mount. This allowed the saddle to sit in the lower hole, and gave the pushrod unimpeded movement along the full travel of the pedal.

The pedal seems to be a lot lighter now. It's not an effort to depress the clutch anymore - there's still some resistance, but nothing untoward. Feels a touch heavier than our Laguna.

Travel is about 190mm now. I don't think I'll be drilling the pedal box again, as the washer shims is strong enough as a permanent solution.

[Mike]

Originally Posted by GreatOldOne

The experiment was (In my mind) a complete success.

I made the angle of the master cylinder shallower by stacking some washers under the lower box section mount. This allowed the saddle to sit in the lower hole, and gave the pushrod unimpeded movement along the full travel of the pedal.

The pedal seems to be a lot lighter now. It's not an effort to depress the clutch anymore - there's still some resistance, but nothing untoward. Feels a touch heavier than our Laguna.

Travel is about 190mm now. I don't think I'll be drilling the pedal box again, as the washer shims is strong enough as a permanent solution.

Jason

I am delighted this has worked out well for you. Are you able to measure the dimension of your pedal pivot to the hole for the rod? My original top hole was around 80mm - the lower hole is around 55mm.
I wonder if Marlin ar not consistent with these hole centres? Maybe Robin and Peter had arond 50 -60mm top holes originally - otherwise they would not have had a full depth pedal travel?
Regards Mike
PS
I have now moved my rod to the lower hole. Only trouble is ....................... I have now embarked on the 'helper spring as well' - why can't I leave well alone?!!

[GreatOldOne]

I'll try and take some measurements tonight.

[GreatOldOne]

Right, these aren't particularly accurate, as it's a tight squeeze in there now, but the distance from the pivot to the lower hole is about 50mm, and from the pivot to the upper hole is about 70mm

[Mike]

Originally Posted by GreatOldOne

Right, these aren't particularly accurate, as it's a tight squeeze in there now, but the distance from the pivot to the lower hole is about 50mm, and from the pivot to the upper hole is about 70mm

Jason
Thanks for these - mine are 55mm & 80mmso I think Marlin may not be consistent with their dimensions. You can imagine how hard mine was with an 80mm fulcrum!
However, you give me great hope, as I have already modified mine to the 55mm hole and from your account, it suggests it will move in to the acceptable territory.

Now, do I fit that helper spring or not...................................?
Mike