Porsche Enthusiasts Club Forum

Currently have an issue which a number of Rennlist users also seem to be suffering from, and nobody has yet come up with a realistic suggestion. Can you help...

Before engine was swapped, I didn't have this problem. Changed the engine, clutch (friction, pressure plates and thrust brg), pilot brg, refaced flywheel. Clutch hyd sys is in good condition. Normal town and A road driving, I have no symptoms. When I've done a period on the motorway or after a spiritied A road burst, when I change gear and put my foot on the clutch, I get vibration or pulsing through the pedal. So it seems that extended periods at mod revs or short periods at high revs lead to the symptoms. Once I've depressed the pedal once, the symptoms go away unless I then have another period at highish revs.

All I can think is that it is related to the thrust brg spinning and being out of balance/true... Anyone got a better idea?? Lucky I can whip the clutch out in mere matter of weeks

I take it this happened on your way home yesterday then?

I've had this problem or similar in the past with a knackered, partially seized pilot bearing. Are there any noises at the time?
The other possibilty is a weak or cracked spring on the clutch cover but I've only hjad that on old clutches not new ones.

No, I've had it a for a while but haven't worried unduly as it's intermittent and, as it doesn't happen most of the time, I end up forgetting about it!

No noises, just a pulsing through the clutch pedal. If it was the pilot brg, I would have expected it to happen all the time. Pressure plate is new. It seems like it only happens when the thrust brg has had an opportunity to 'spin up', like it's going into resonance, then it transmits vib back through the clutch fork to the slave cylinder. There are 3 other people complaining about it on Rennlist...
??????

This happens with my car too, exact same symptoms.

Have you found what it is yet?

Stuart

Could it be some Contamination on the clutch plate?

Was a new RMS fitted at the same times as the engine?

Ford had a very similar problem on the MT75 gearboxes and that was the release bearing guide wearing

For the record, I thought it'd be worth posting the outcome of this problem so that others can benefit in the future...

To reiterate, buzz through the clutch pedal at high revs. Found that the clutch thrust bearing was tight on the pressure plate - removed a spacer and refitted. Also, clutch guide tube was worn so replaced it - however this could have been caused by the thrust bearing not centering itself properly.

So, all back together now, redline test carried out, no buzz!!!!!

Getting quite good at changing clutches now...