unexplained smell

I just noticed a strange smell and am kinda wondering what's up. 83SC 182,000 miles,daily driver, I've owned her for about
a year and a half,put about 30,000 miles on her and I just for the first time redlined
her and popped the clutch ( I was sitting at a light up hill ) I smelled a really bad smell and the one thing I found funny, NO
tire spin, just bad smell, she took off but
it wasn't no neck jerkin rocket launch, just
a normal take off, with bad smell, maybe kinda like rubber,but again, no tire squeel
or no smoke, oh, yea, I'm runnin BF Goodrich
Comp T/A VR4's if that makes a difference.
What do ya'll think this is ?... Clutch maybe ?

The same exact thing happened to me the first time I redlined my 930. This was about 2 days after I got it, and it really scared me as I thought I had damaged my dream car. But this was 7 months ago, the engine has been running very strong all this time, and I never smelled it again.

Clutch slip

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Leland Pate

___79 SC Targa

Yep, my guess too. Hard to describe the smell though, just kinda pungent.

I'm betting that it does it again soon, and eventually when it is shagged, third gear uphill will be like a variable transmission car - constant revs, slowly increasing speed.

Then a new clutch....

Cam

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Cameron Baudinet
1975 911S

SC's between 1978 to 1983 had a rubber centered clutch. If yours slipped, maybe you were smelling the rubber burning. Since your car has so many miles on it, I'd assume that the clutch has been replaced (at least) once. If you have the original records, see if the replacement was with one of the spring centered clutches or one of the "rubber centered (exploding) clutches", as described in Bruce Anderson's PORSCHE 911 PERFORMANCE HANDBOOK (pg 47, to be exact).

I can quote from the books with the best of 'em!

Good Luck,

Bill Wagner

[This message has been edited by Bill Wagner (edited 07-05-2000).]

My clutch was replaced at 90,000,I've got the
books! what can be done about slipping clutch? Is it adjustable or am I looking at
having to replace it ?

Chuck:

If your clutch had been replaced, let's hope it was with the steel springs in the center, which, by the way, is an old style, but still useable in those cars which came with the rubber disc.

My rubber disc exploded at the track one day, at Summit Point, and after being driven to Autothority without the clutch (luckily there was scant traffic between Summit and Al's), we replaced the clutch with the spring centered one. It has been going dtrong ever since (and I guess I don't abuse it, even on the track).

You can adjust a slipping clutch, but only if it is slipping due to misadjustment. If it is slipping due to abuse and premature wear (not that you would have done this, perhaps by the P.O.?), then you would have to replace it. My records show that we did the clutch in 1987, at 39,769 miles, and it cost $827.50 for new clutch disc, new pressure plate, and new throw-out bearing, labor and parts.

Adjustment is done from under the car, near the clutch cable clevis, which can be lengthened to keep from slipping. But there is a fine line between not slipping and excessive free-play. Do you have a friend who can help you?........Andras

I've got 60,000 miles on this clutch !
How long does a clutch last, The P.O.
never raced the car,neither have I !
Frmon what I've been reading I'm about ready for a new clutch. The Sachs seems like a
good one for the money, any other suggestions?

The 'smell' is burnt 'phenolic' ... and it has been the same for brake shoes (remember drum brakes?) and pads, as well as clutch disks ... since the dawn of history!!! I have actually seen SMOKE drifting off the back wheels on cars with the emergency brake left 'partly on' ... the smell is ALWAYS the same! It was in a grocery store parking lot and the lady was a bit concerned why her car was generating such an awful odor ... brakes can generate a LOT of heat when dragging for two or three miles!

Well, in a previous incarnation Fitchel & Sachs were building OEM clutches since the '40's for VW & Porsche ... including the original '53-'54 550 Carrera's that won the Mexican Road Race ... American translation of Carrera Pan America. They also made the clutches for a rather successful 917 series of race cars ... just a bit of history from the days when the only water carried in Porches was to wash the windshield!!!

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Warren Hall
1973 911S Targa


[This message has been edited by Early_S_Man (edited 07-06-2000).]

Chuckr:

First off, let me say that when I said " I can quote from the books with the best of 'em!", it was a joke, and I hope you took it as such.

I'm not an SC expert, but I've never heard of a clutch that isn't adjustable. Typically adjustments are simple. Hydraulic clutch's to some extent, "automatically" adjust for the wear on the clutch disk, but may need adjustment of free play (and sometimes pedal height, depending on the type of car it is) particularly if the flywheel has been resurfaced. I don't think your SC is hydraulic, but rather a mechanical linkage (it uses a cable) and I don't think there is any type of mechanism to automatically adjust this for clutch disk wear(some cars do have an automatic mechanical adjuster, but I don't think Porsche is one of them).

I know the Haynes manuals aren't much, but I'm looking at one while I'm reading this, and the procedure for your car IS outlined in it. If the clutch is not adjusted properly it means that your clutch will not make adequate contact with the flywheel when it's engaged. This will cause the clutch to slip, which is probably what produced your odor.

To see if the clutch IS really slipping, find an area where you can safely drive up hill at a reasonable speed (35-45mph). Put the car in one of the higher gears and FLOOR the gas pedal. The clutch should be fully engaged when you do this (i.e., you should not be applying ANY pressure to the clutch pedal). When you do this, watch the tachometer and see if it shoots up. Quickly take your foot off the gas and see if the RPMs "lock" or settle down to a lower level. If this happens, even slightly, your clutch IS slipping.

If it is slipping, try adjusting the clutch or have someone adjust it. I wouldn't order a new clutch just yet when a 5 minute adjustment may take care of the problem. If the previous owner kept ALL of his records, and you now in fact have over 90K miles on it, I'd be inclined to say that getting 90K miles out of a clutch is very good. Don't be surprised if you're looking at a new clutch.

I hope this helped,

Bill Wagner

[This message has been edited by Bill Wagner (edited 07-07-2000).]