How do I know if clutch is bad?
 

Hi - new 911 Targa owner here. Just bought a 1981 with 115K miles on it from a guy who owns a Porsche repair shop. I paid $12,000 for it. Car is well documented, starts well, handles well, has had chain tensioners added, etc.

But when I was test driving it, I thought the fact that it did shift all that smooth was because I had not driven a stick in about 15 years. I ended up buying the car, and I think that clutch is about to go. Symptoms include:
- clutch is the stiffest I have ever felt in more than a dozen sticks I've owned. Is this typical of a 911?
- really have to pull it into second gear, almost like a two step process
- downshifting from 3rd to 2nd it will grind about 50 percent of the time
- from stop, putting it into first, it will also grind about 20 percent of the time.
- I have noticed a slight burning smell when I pull the car into the garage.
- there does not seem to be any "slipping" that I have experienced before when clutches go bad on other makes.
- When I bought the car, I told the guy it seemed odd that it was doing this - he said I just needed to make sure I had the clutch pushed all the way in. Plus he said that "downshifting is over-rated - you should just use the brakes." (Cramming the clutch all the way to the floor makes no difference.)

My questions:
- what does a clutch replacement typically cost?
- does this sound like a clutch, or tranny or shifter problem?
- apparently, there was a "short shift" kit installed in the car at one point - could this be the problem? If I replace the clutch, should that stay or go?
- is it reasonable to take it back to the guy I bought it from to replace the clutch at cost (he owns the repair shop) - he MUST have known the clutch was going to go. (I don't know if it is buyer's remorse or not, but I feel as though I was taken for a ride.) I know - I should have had a PPI, but did not. (Lesson learned for next time.)

I really dig this car, but this issue has more worried. Any responses are very much appreciated!

Thanks
RTC

The clutch on a 911 is very stiff ! Shifting from 1-2 is two step process, and from 3-2 is a not easy either. A part from that I cant tell you how to check the clutch but you will get more answers. ;)

Every time I let someone else drive my car they make some grinding, but I have learned to drive my car. I think its take some driving to know yours.

The 915 transmission used in your car will exhibit , to a certain extent, the symptoms you have discribed when the synros become worn. Even when new shifting must be done deliberately, speed shifting is a no no. The short shift kits will accentate the problem.

Now to your original ? Those cars, oem, used a rubber ctr clutch which when it went bad sent bits of rubber material to jam up the friction surface of the clutch making shifting almost impossible. I would be surprsed if the rubber ctr clutch held up this long, most were replace years ago, but you never know. The normal failure mode of any spring ctr clutch is that as the engine revs it does not accelerate the car, this is often accompanied by a metalic stench form the metal rivets of the clutch rubbing on the flywheel. A third failure mode may be of the pressure plate itself, I have had one crack, but springs go bad thru heat/time, the symptoms are the same as for a worn clutch because of the loss of clamp. any or all of these problems may be present in your car. If you are unfamiliar with these cars I would take it to a shop that you trust for inspection.

when the disc is thin, the release geometry of the pressure plate is thrown off, and you get a stiff pedal.
if the clutch is not adjusted so it will release the disc completely, shifting will be difficult.
if you have a short shifter, shifting will be more difficult than if you had the stock one. anytime the length of a lever is shortened, the effort needed to move the lever is increased. simple physics.
have another shop check and adjust for you, and then you may need to go back to the seller and call BS.

Thanks!
 

Thanks for the feedback - I have an appointment scheduled on Friday for a new mechanic to check it out. I appreciate your info!
RTC

The 911 clutch is very stiff and as other mentioned above that in itself is pretty normal. Shifting from 1-2 is typically something that requires double clutching in the pre-87 Carreras. Making sure the clutch is fully pressed in is a part of the technique you will develop. I have similarly noticed the burning odor and my gears engage but I get a scraping noise about 10-20% of my gear shifts...taking it to my master tech tomorrow will let you know if I Learn anything new.


A

1985 911 Carrera coupe Grand Prix White

U can't shift ?

I'd start with adjustments first. Pelican has a good write up at Pelican Technical Article: Clutch Adjustment - 911 (1965-86) - 930 Turbo (1975-86) to get you started. My 915 transaxle is pretty worn, but still works. I don't have to double clutch, but shifting does need a bit of finesse.

there is no doubt you have worn fifst and second gear synchos. not the end of the world though. take your time and learn to shift a 915.
no double clutching should be required. and 911s dont typically have stiff clutches. that is BS.
my 78 clutchgoes in smooth as silk .

a few tips.
replace clutch cable and adjust properly ( cheap and good pm ) even if you end up putting a clutch in you will have a new cable.

when shifting from first to second you need a pregnant pause in the neutral plane, that is all

slip in to first when rolling to a stop

will make life easier and get more life out of your gear box

As others said, it probably just needs adjustment, to soften up the pedal. It'll never shift like a new car, of course. And I'd learn the double-clutching technique, even if it is not really necessary. I find it kind of fun, actually, and do it instinctively now.

From what you've said, it looks like you got a pretty nice car for 12K, even with the worn synchros. Even if it does end up needing a new clutch, I don't think you overpaid.

My '84 had a clutch pedal that would have worked a power lifter to death. Adjusted as per the FSM and it is as light as my Toyota BJ40 and smooth as butter.

I would hope he didn't pay more than that. That original post is from 2002.

I really wish the board would prevent 12 year old bumps.....