Clutch replacement

quik550 · quik550's Garage

Coming into turn 5 at Road America my clutch pedal felt soft and did not return with spring. Car smelled of burning clutch and apparently smoke came out the back. Got off there, clutch still worked, but soft. Car smelled for an hour! Had a friend readjust the pedal and cable (threads on cable were stripped at 25mm, perhaps causing slippage). Drove car again about three laps, no smell, worked fine, then three laps later with some smell if I let the engine pull the car down at all. Drove home fine. Figure pressure plate is burned, but how do I know if I have to replace the whole clutch and cable? Please respond in non techie language as I am not mechanically inclined.

Jon Merck · 06-03-2006, 06:44 PM

What kind of tranny?

quik550 · quik550's Garage

It's a 915 that was put in a rebuilt 74 911S with 85 930 LSD.

LakeCleElum · 06-03-2006, 09:14 PM

If it's now adjusted correctly, you will know if it slips or "chatters".....Check for slippage by flooring it in a higher gear a fairly low speed. You certainly used up a lot of clutch material, but it doesn't always mean the end of it......

dentist90 · dentist90's Garage

Unless you want to do a 2nd engine drop in the near future, probably figure on new clutch friction disc, pressure plate and throwout bearing with resurface of flywheel surface. If you can SEE part of cable adjusting threads are worn it only makes sense to replace the cable as well. Clutch pedal not returning is suspect, better check clutch pedal springs and pedal bushings. Nobody wants to pay too much $$, but with a clutch I think it is a pretty rare situation where you keep one component when something else has suddenly failed.
I cooked a clutch a few years ago on the street trying to make a quick 3-point turn. Engine revved up but we didn't go anywhere... I can still smell it! Once everything cooled down it worked OK. You can do a little test by keeping your foot on the brake pedal while you slowly let the clutch out. The engine revs should drop immediately. If you can sense some slippage either the pressure plate has lost tension or the friction disc is wearing out/glazed.