86' 951 Clutch Disc

Frank Matchura · 03-19-2006, 02:10 PM

Approx. every 25K the clutch disc looses one turn of the inner small spring and jams either between the flywheel or the pressure plate. This has happen twice and both disc's were Sach's and the correct #'s. I have tried to find out what would cause this problem from Porsche, Excellence Mag. and others. Not even a response.
I want to put this guy back on the road but, I want to fix it right this time. Original owner w/ 78K on the Odo. Help

sayporsha · sayporsha's Garage

It sounds like you are using the "correct" clutch for the 86 car. Problem is, well, it's a problem. Jettison that and go with the 944 Turbo S, a.k.a. "Cup" clutch. It does not have those tiny springs that keep giving you trouble.

Use this type:
http://www.*****************.com/product_p/pp951clutchkitsport.htm
Not this type:
http://www.*****************.com/product_p/pp951.116.911.00.htm

Britwrench · 03-20-2006, 08:38 AM

In general these clutches with normal use last a long time, if you have got through three of them in 78k miles then we need to know the "rest of the story"

Frank Matchura · 03-20-2006, 08:38 AM

Thanks for the quick response. I thought the problem might be a spring quality issue on the first failure but, two years plus later and another failure didn't make good sense? Does a Cup, "S", disc work with the std. 951 pressure plate or do I have to buy the whole tamale?

Frank Matchura · 03-20-2006, 08:49 AM

I know clutches last longer than this and I am not a street light or a raser. I did the work myself and as mechanical engineer with many years experience rebuilding cars I have not experience this type of failure. Alignment to the shaft went with no problem as well as the rest of assembly. Any thing specific as to the "rest of the story" I would be happy to provide. I am really stumpt.

sayporsha · sayporsha's Garage

I'm with Britwrench on the longevity issue. I put about 50,000 miles of HARD use on a regular 951 clutch and it looked fine when I replaced it. It would be good to know why you're having such a high failure rate, but if you go with the Cup clutch chances are you'll be fine from here on in.

The Cup clutch disc will work with a regular PP, but I don't know if the Cup PP is different, has a higher clamping force, etc. Assuming your PP is OK, I would try to get it and the flywheel machined first to properly bed in the new disc.

Frank Matchura · 03-20-2006, 10:18 AM

Good suggestion of the re-surfacing. I have two PP to choose from and both have very little wear on the fingers. For the record I replaced the PP, Disc and Throwout Bearing on the last go around. Thanks for your help and I'll let you know what the end results will be.

nize · nize's Garage

i've put over 80k miles on my original clutch, and then over 90k on the second clutch.

the factory clutch can easily last 50k miles of 'normal' driving. if you're going through the clutch every 25k, you're doing something really bad with your car.

daniel951 · 03-21-2006, 08:56 PM

i actually have a cup clutch for sale with like 1k miles on it. I have one guys interested in it now but if he backs out its up for grabs again

Frank Matchura · 03-22-2006, 06:47 AM

Let me know if it doesn't sell. Bye the way, I have driven more vehiciles in my driving life w/sticks than automatics. I have a 60' 356 with over 600K and one clutch and that was with a lot of stop and go SOCAL freeway driving. I replaced the clutch only because I rebuilt the engine @ 230K. I don't drive like a little old lady from Pasadena but, I don't race the car either. I just drive it like like it was designed, for fun. I miss it but, I won't put it back on the road and experience another failure if I can help it.