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rumplestiltskin

Original Poster:

1,084 posts

110 months

[news] 
Wednesday 30th November 2005 quote quote all
With my 996TT coming up to 25k miles on its original clutch and the fact I do more stop start driving than I used to, I am pretty sure the clutch will need replacing some time soon.
What are the tell-tale signs that a clutch could be nearing replacement? Clutch judder from standing start? Clutch slip (what exactly is that?) Difficulty getting into gear?
When the car was in for a major service 3 months ago I asked the OPC to check the clutch for wear & they said it was “fine” though quite how they knew this I don’t know.

Any advice appreciated.

nel

4,024 posts

129 months

[news] 
Wednesday 30th November 2005 quote quote all
Hopefully it won't need doing as early as that! If the car is driven with some sympathy when pulling away from standstill then there's no reason why 50k miles shouldn't be achievable, as was the case for my 993TT.

Clutch slip is normally most obvious when giving the car full beans in a taller gear, e.g. 4th or above, particularly up a hill. You'd notice it - the revs rising for moment and the cars performance trying to catch up. Can also be accompanied by the delicate smell of fried clutch if it occurs at lower speeds.

Supposedly another good test was to try and pull away from standstill in 3rd. If the car stalls, the clutch is OK. I've never tried this one personally.

Anyway, I'd say that there is no need to pre-empt it. If for some unfortunate reason the engine is out of the car, then get the clutch done. Otherwise just keep enjoying yourself until the death of the clutch starts to manifest itself.

barry_j

605 posts

124 months

[news] 
Wednesday 30th November 2005 quote quote all
I agree with what nel said. Of course, unless you've owned the car from new then you won't know how its been driven and whether previous owners have abused the clutch. Depending on that a clutch can last from zero to 60k miles. I think around 45k miles is reasonable. Tell-tale signs are that you will notice the rev counter shooting up but the car not moving as quickly as you would expect from the revs (more noise, less acceleration). Its most evident if you put your foot down hard, are going up hill, are in a higher gear or a combination of all three. When you get out of the car, the foul smell of a slipping clutch is unmistakable. Once it starts to go, then the decline is fast so don't leave it too long to get sorted otherwise you may damage the pressure plate which will add £500 to the bill.

Finally, when it is time to get it done, DON'T GET FOOLED. Many OPCs and Independants will tell you that its a 12hr job because the engine needs to be removed. It doesn't need to be removed and so its a 7hr job. Your costs should be:
- Labour (between £350 and £700 depending on Independant or OPC)
- Approx £600 for Genuine Porsche parts (996tt clutch; others should be cheaper)
- VAT

verysideways

9,300 posts

160 months

[news] 
Wednesday 30th November 2005 quote quote all
As an addition to what has already been said (which i agree with entirely), you can tell how much wear a clutch has experienced by the self adjusting mechanism. Because the 996tt clutch is hydraulically activated, there isn't a cable to stretch, so the self adjusting mechanism tries to keep your pedal biting point in about the same place throughout the life of the clutch. Since the clutch wears, this adjuster moves. So by looking at the position of the self adjusting mechanism (which i assume is visible from under the car - on ramps) you can guage roughly how worn the clutch is.
Hope this helps.

dakkon

6,523 posts

141 months

[news] 
Wednesday 30th November 2005 quote quote all
On an older Porsche say a 3.2, can you still replace the clutch with removing the engine?
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nel

4,024 posts

129 months

[news] 
Wednesday 30th November 2005 quote quote all
barry_j said:
Finally, when it is time to get it done, DON'T GET FOOLED. Many OPCs and Independants will tell you that its a 12hr job because the engine needs to be removed. It doesn't need to be removed and so its a 7hr job.


Just a caveat here - I don't know if this is necessarily true for the 996TT, but certainly is for the 993TT (bitter experience).

In theory clutches can be changed on 911s by removing the gearbox and tilting the front end of the engine down. This is OK on 2WD versions, but on 4WD versions the propshaft heading off to the front wheels complicates the process, as there is really bugger all room to insert the input shaft straight into the clutch & flywheel assembly.

When I had the clutch on my 993TT done by a (crap, it transpired) indy in Paris, he did it without removing the engine. 3000 kms later I was having clutch problems again. It turned out that they'd broken the pressure plate at fitting, presumably due to the lateral loading when wrestling the gearbox back into place with sod all clearance. The indy that I use now, quality service to date and judged trustworthy, says that he'd never recommend doing this job with the engine in the car on a 4WD variant. Better do the assembly right first time with the engine out. He redid the work (while uprating to GT2 clutch/flywheel) with the engine out and the other garage's insurance are reimbursing me.

If you factor in the extra time off the road and the potential for cocking it up, engine out is the way to go for a 4WD (993) in my opinion. Anyway, while the engine's out you can get lots of other little things done easily - cam-cover seals, plugs, etc.

No doubt 9M would have a point of view on this matter - any comment?

Marquis_Rex

7,377 posts

127 months

[news] 
Wednesday 30th November 2005 quote quote all
My clutch is on the way out RIGHT now. The pedal started getting progressively harder to operate until one day it slipped( felt really "free revving"at peak torque rpm- so I no longer revved it.
It's just what I need :rollseyes: as I'm in the process of trying to sell it and the amount I've looked after my car and condition I expect good money.
So It's booked in, after which time I'll start putting the adverts up.
Oh and the milleage covered is just under 50,000 miles just like Nel says. Oh well, if I get stupidly low offers made on the car I simply won't sell it now and it'll come to Germany with me....

barry_j

605 posts

124 months

[news] 
Wednesday 30th November 2005 quote quote all
nel said:
barry_j said:
Finally, when it is time to get it done, DON'T GET FOOLED. Many OPCs and Independants will tell you that its a 12hr job because the engine needs to be removed. It doesn't need to be removed and so its a 7hr job.


Just a caveat here - I don't know if this is necessarily true for the 996TT, but certainly is for the 993TT (bitter experience).


Yes, it is true for a 996tt. I can verify this from first-hand experience; mine was done by an OPC without removing the engine. I also spoke to JZ-Machtech who verified that the engine does not need to be removed. With any major mechanical work, there is always the potential to get it wrong and I'm sorry to hear about your experience nel but (IMHO) I feel that had less to do with the engine not coming out and more to do with the competence of the mechanic doing the job.

In your case nel, the other garage's insurance is paying for it so, of course it makes sense to take the engine out, charge them the extra labour and get the extra jobs done at the same time.

>> Edited by barry_j on Wednesday 30th November 10:54

verysideways

9,300 posts

160 months

[news] 
Wednesday 30th November 2005 quote quote all
My indy (who i rate, and so do quite a few other people) took the engine out to do the clutch on my 993C4S. They can take an engine out and put it back in much quicker than it says in the Porsche book.
edited for crap spelling

>> Edited by verysideways on Wednesday 30th November 10:53

egbert

449 posts

109 months

[news] 
Wednesday 30th November 2005 quote quote all
Had this done recently-the tell tale signs were-slightly "rough" feeling through the pedal when pressing clutch-similar feeling to a slightly catching cable.(although obviously not as it's hydraulic)

whiff of clutch every now and again as well.

My independent told me it was engine out and it seems he's done a good job-saying that the price was on the high side considering other quotes.

egbert

449 posts

109 months

[news] 
Wednesday 30th November 2005 quote quote all
and it happened at 38k miles.

rob05

1,194 posts

116 months

[news] 
Wednesday 30th November 2005 quote quote all
Maybe this is useful,or not!
I've never had to change a clutch once in any of my cars and my old 2.5 boxster was sold with 70k on the clock.
I never spin the wheels and always take it out of gear in traffic.
Imo driving style has a lot to do with the how many miles you can expect from your clutch and brakes.

turboguru

448 posts

118 months

[news] 
Wednesday 30th November 2005 quote quote all
I asked the same question about the clutch on my 996 TT and was told by a specialist that the clutches will do anything up to 50 on our cars as they are so over engineered for the power. Mine had a new one at about 30k but it has now done 44k and feels great - as you know I use her everyday and do about 1-2k miles a month without any problems. A new clutch fitted from an OPC will cost you about 2k as they are bound to try and con you about the flywheel needing changing too. An independant will do it half price. Make sure the fluids are all changed at the same time too. I wouldn't worry about it, I am told that when they go they really go so just wait until then and for now put it out of your mind. Put a couple of Grand to one side and when the time comes get it done.

rumplestiltskin

Original Poster:

1,084 posts

110 months

[news] 
Thursday 1st December 2005 quote quote all
I have been told that over time the clutch plate can get dust etc on it & esp if you are very sympathetic towards your clutch and its a good thing every so often to do a full bore start to get rid of this....any thoughts on this?

henry-f

4,646 posts

133 months

[news] 
Thursday 1st December 2005 quote quote all
I`m not aware of any benefits to ragging the balls out of any component.

Clutches need changing for a number of reasons and in truth there is no mileage "range" for their changing. It depends entirely on how much they are used and the way the driver operates the clutch each time they use it. Anywhere from 3-4k miles right up to 150k miles are obtainable, (ranging from someone doing loads of little stop start journeys and being massivly hard on the clutch to someone spending all their life on the motorway. It`s very much like brake disc / pad wear.

We change more clutches for their getting stiff as they age, rather than slipping as the friction plate wears.

Typically you will need to change a clutch if :

It is very stiff to operate.

There is excessive judder on take up in 1st or reverse gears, (often a sign of clutch plate / flywheel - pressure plate contamination or damage.

Difficulty in selection 1st gear with the engine running and the car stationary, (and the gear selects easier if you turn the engine off).

Clutch slipping - car in 3rd or 4th gear engine at 3,000 rpm foot well off clutch, accelerate hard and the engine revs up without the car accelerating the appropriate amount, ie the engine seems to "free rev"

There is exsessive noise when you operate the clutch with the engine running. Usually a release bearing.

Unusual pedal feel - this might be the slave / master cylinders rather than the clutch unit it`s self.

That should cover 90% of the reasons !

Henry

rumplestiltskin

Original Poster:

1,084 posts

110 months

[news] 
Thursday 1st December 2005 quote quote all
henry - thanks for this.
I have non of the symptoms below, except judder in reverse - quite bad usually. Should I get it looked at ?

BliarOut

60,278 posts

127 months

[news] 
Thursday 1st December 2005 quote quote all
Clutch mileage also depends very much on where you live/drive. Here in the fens there are no hills and hence no hill starts, ever. I've not replaced a clutch on anything in twenty four years of car/bike ownership.

silver993tt

8,574 posts

127 months

[news] 
Thursday 1st December 2005 quote quote all
is it actually possible to tell in any way if a clutch has been previously changed (stock of course)?

riverproaudio

966 posts

109 months

[news] 
Sunday 10th September 2006 quote quote all
To bring up an old subject, It seems that my clutch is going, 3k/4k revs, boost shoots up and engine revs shoot up, then the car starts to move slowly as it starts to grip. The question I have is, I have only done 18K miles! I do not drive the car very hard. I do not do a lot of town driving> The car is fitted with the X50 upgrade to 450bhp, but surely it should not of gone so quick. Any thoughts on the subject would be great.

flemke

19,475 posts

125 months

[news] 
Sunday 10th September 2006 quote quote all
riverproaudio said:
To bring up an old subject, It seems that my clutch is going, 3k/4k revs, boost shoots up and engine revs shoot up, then the car starts to move slowly as it starts to grip. The question I have is, I have only done 18K miles! I do not drive the car very hard. I do not do a lot of town driving> The car is fitted with the X50 upgrade to 450bhp, but surely it should not of gone so quick. Any thoughts on the subject would be great.
Other possible causes of rapid clutch wear include not depressing the pedal sufficiently when you change gear, applying the power prematurely on an upchange, and slipping it to effect a smooth take-off from standing.
It's easy to get into an unconscious habit of doing any of these things.


(Btw, are you sure that the boost shoots up in these situations, with the engine only lightly loaded?)
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