Clutch Slip or Something else?

[Mignon]

Hardly surprising. It slips as the torque builds up and then stops slipping above peak torque rpm. What you had bemused us by initially was failing to spot the low rpm slippage and only mentioning the higher rpm catching up.

[VEX]

I agree, but as you say, it was the missing 2k slip I was missing.

If I enjoy it now, whats it going to be like with a fully engaged clutch at 2K!

[PaulKemp]

I had the same conundrum with a Corsa VXR, the owner (a friend) described similar to the OP, it’s not something I have experienced before, I’m used to the classic rev counter goes up speed does not.
I took with me on the test my cousin an very experienced lorry mechanic.
It didn’t feel right but it wasn’t clutch Slip as we knew it but definitely wrong, I then drove the car and it felt like the clutch was just beginning to be defeated by the torque exactly how Mignon described it. Strangely it only happened in the higher gears and I wondered if the traction control was holding torque back in the lower gears and the overboost facility in the higher gears was enough to just break the clutch bite.

Sorry for the long winded explanation I’m nearly there.

The upshot is that I pulled the gearbox of for the young man and the friction plate was indeed worn and there was just the hint of part of some rivets holding the friction material worn.
In my experience on an older car this would not have been felt whilst driving but modern turbo cars with overboost and the clutch getting a bit hot could have been enough to just to cause the symptoms described.

I have just checked the old friction plate and 4 out of 8 rivets on 1 side show signs of wear

[PaulKemp]

Just to add we did the handbrake test.
Pulled it on and loaded the clutch from standstill, the clutch did not slip

[PaulKemp]

[PaulKemp]

[Mr2Mike]

PaulKemp said:

I then drove the car and it felt like the clutch was just beginning to be defeated by the torque exactly how Mignon described it. Strangely it only happened in the higher gears

That's not strange, it's exactly what would be expected with a worn clutch. Higher gears place greater and more sustained load on the clutch.

The bottom line is that if engine RPM and road speed don't rise proportionally during acceleration with a manual transmission then something is slipping, either the tyres or the clutch.

Edited by Mr2Mike on Wednesday 6th December 17:42