Need Advice With Clutch Pedal Adjustment For Twin Plate Clutch

[BakemonoRicer]

Currently have an ORC 559 Twin Plate Clutch Installed....but need some advice in terms of adjusting it.

The OEM Service Manual suggests a clutch pedal height of 190mm, but at the moment my pedal is quite a bit lower than this at approx. 160mm so that the 'engagement point' is lower.

My technique each time I push/release the clutch pedal needs to be very precise otherwise I get a jerky shift etc. I'm finding it quite difficult to shift from 2nd to 3rd, as I seem to be getting a thud/thump noise occurring.

Would the lower pedal height be causing too much preload on the release bearing? Or maybe causing engagement to be 'harsher'?

Any advice appreciated....thank you.

[Dan_J]

cant answer this directly to your issue although when i took my clutch pedal out to strengthen with more welds and flat bar i also did grind the alignment nut off and welded a new one on the opposite of where it was originally so that i could get more alignment out of the pedal effectively raising the pedal height 10-20mm of adjustment

[GTSBoy]

The absolute pedal height will depend on the amount of movement in the clutch itself.

The most critical reason for adjustment at the pedal is to make sure that you have a non-zero and not too large amount of free play at the top of the pedal stroke. You want some freeplay so that the mater is not continuously loading the release bearing. You don't want too much because a large amount of free play at the top of the stroke feels bad and makes the clutch hard to use. You stab the clutch and it moves 10-20mm with no resistance then it hits the mechanical load and instantly becomes whatever force is required to push the pedal down. Sucky sucky.

tldr; just make sure that the amount of freeplay is right, and if you still suspect that there's something wrong, you might want to get an experienced mechanic to take a look, because there might be a problem hiding in the clutch itself or the slave or the fork, etc etc.