Clutch release lever, modified

Hi Fellow HPAers

Just pulled the T5 gearbox off the back of my 1990 VN Commodore NZ Six series race car and upon separating from engine discovered the clutch release lever has been somewhat modified.

It has a 75mm long x 40mm x 40mm piece of solid steel welded to it, see attached photos for better understanding. I'm not sure why it would have been modified that way and no one to dates been able to say why apart from adding mass.

Clutch is a Puk clutch clamp load is 2700lbs

Be interested if anyone can shed more light on why you would modify in such a way.

The clutch worked okay but it was either on or off.

Look forward to your assistance and have a great rest of the week.

Cheers Mal

That's weird af! Never seen it done before and can't think of a reason to do it - anyone?

The on-off clutch will be down to the design of the friction plate as, with very few exceptions, they have no Marcell spring to give a progressive take up.

This video should explain it better to you - https://www.youtube.com/watch?v=I2-UXYu5l1Q

Hi Gord

Thanks for taking the time to answer and also the great explanation video.

Yes your weird af comment is one I've heard many times in recent days and its got everyone beat.

Going to replace clutch release lever with a brand new one, new pivot ball and in the interim a new HD clutch set up from Exedy.

Just putting a fairly stock motor in place whilst I rebuild the race motor as a cylinder decided enough was enough.

Thanks once again for replying.

Cheers Mal

Any chance to ask the previous owner, or shop that worked on the car, "what was this for?". It would suck to break a new part because of some resonance issue they chased down and solved.

Hi David

Thanks for taking the time to reply. Unfortunately the previous owner hasn't touched the clutch so was none the wiser and the original builder of the car isn't interested or can recall what he did as he has moved on from an interest in motorsport.

Agree what your saying but it does appear to stump everyone that views it as to what it's actually achieving. The car was really well built and this is probably the only modification that seems out of character to the rest of the precision work.

Thanks once again for your assistance.

Regards Mal

The only thing that comes to mind is that possibly it could prevent flex or bending in the clutch fork. It's a long shot but no other explanation springs to mind. The on/off nature would be a result of the actual clutch material though and not the fork or modifications to it.

Hi Andre thanks for taking time out to respond. It is a strange one that's for sure. I can understand bracing the fork but not the need for a huge chunk of steel hanging off the back.

I've order a nice new Dellow conversions clutch release fork, pivot ball etc and setting it up as designed and will see how it performs.

By the way congrats on the Endurance race win at Highlands.

Regards

Malcolm