Quest for the Wholy Grail (Answers to "Sticky" Clutch issue)

[edge]

Not having the same issues but bumped into an Audi tech in the gym and asked about the sticky clutch on return with spirited driving, he said it was due to heat transfer and to lay off the right pedal. He said its time to change the clutch!

[PetrolDave]

He said its time to change the clutch!

Some owners had this problem from new so it's not just a clutch wearing out problem, they also did it from the factory.

[The_Coat]

The original owner of my car got in touch via this forum last year, after speaking to him it turned out the clutch return pipe was replaced at around 3k on my car due to the clutch sticking.

[nikkak77]

As said previously, the clutch itself has been changed entirely.

About the pedal, i don't know what to say. It seems perfectly alright.

Anyways as an update form the workshop, the slave cylinder showed signs of fluids, which obviously should not have. As such a new oem slave cylinder has been ordered. In addition a new release bearing and a guide guide sleeve has been ordered as well despite lack of apparent wear signs.

Tomorrow a VERY careful examination of the clutch, flywheel and pressure plate will take place.


Thanks to Scott's post on the USP line, i managed to find a local specific workshop that can custom build any type of pipe under similar specs as long as i bring him the original return pipe. So tomorrow i will pick it up from the workshop and have it custom made, just to make sure.

[coffey555]

My pedal feels ok as well but it does sit 5mm higher than the brake pedal and they are supposed to both be at the same height in a line.

Some people have reported that parts of linkage can breakdown which in turn affects how the pedal returns.

[Scott Long]

I will check to see my height but I think it's same as brake.

[nikkak77]

Ok guys, I just visited the workshop this morning that has taken apart the clutch. Below you can see pics of the clutch, flywheel and pressure plates.
The LOBA Sachs stage 2 has been installed and driven for about 2.5km roughly. As you can see aside from burn marks on the clutch and pressure plate, there are grooves on the clutch!

Correct me please if I am wrong but this is not normal for a 2.5k driven distance, with no launching!

Anyways as regards the vacuum system there were no apparent leaks, but just to be safe everything will be replaced by Audi OEM parts again. The guide sleeve too is going to be replaced, although it seems ok.

In any case, the technician at the workshop was surprised by the looks of the clutch and the pressure plate.
Truth be told, I have just also contacted LOBA in Germany and waiting fro their feedback.

Any thoughts are much appreciated.

[adsgreen]

that looks to me very much like a slipping clutch.
Problem is why...

Could it be that when the pedal is stuck it causes the clutch to slip?

[coffey555]

Is the clutch level with the brake pedal?

Mine wasn't by a slight bit and one of the Audi Techs said my pedal itself was broken up somewhere in the pedal box.
The explained the first part of "Free" travel before I felt resistance.

It might not be the same as mine, but worth getting it checked. Audi said that because of this free travel the clutch wasn't engaging/disengaging fully, which lead to sticky clutch and ultimately fubared the clutch.

Changing everything out again is just going to end up with the same result surely?

And you said yourself you had a light feeling at the start of the pedal stroke? And that your clutch pedal is not at the same height as the brake?

Regardless of what the mechanic has said, surely it needs to be changed out if only to rule it out?

Personally I would replace the clutch pedal assembly like Irishmike did in the above post keeping everything else as it is.

The clutch and flywheel is not pretty but plenty of material left and it will certainly last long enough for fault finding purposes.

If you find the new clutch pedal fixes the problem you can either run the second clutch until it dies or replace with a new one.

[TonyHayers]

Can't believe a definitive answer to this problem doesn't exist yet. Good luck and I hope the problem gets fixed for you.

http://www.audizine.com/forum/showthrea ... -RS4-Owner

Audi stock RS4 pressure plate is a self adjusting design, it was the cause of my problems. I have replaced clutch and pressure plate with a non adjusting design, and replaced slave cylinder and got a steel braided hydraulic line. Clutch in my car grabs hard and feels great.

Erm, sorry to sound like an ass, but I read your post on AZ: "Car has 109k on it, 1 owner, clean carfax, good maintenance records but original clutch". Original clutch after 109K?! I think I found the problem!

[TonyHayers]

I don't believe there is one definitive answer to this, mainly because it's not one simple symptom. It's very clear that there are a number of (sometimes subtly) different symptoms for different owners, and therefore different solutions. Some people have replaced the return pipe and all good, some people have replaced the entire assembly and all good, some people have tried both and still experience issues. The OP seems to have a new additional symptom (I've not heard of it before anyway), where the pedal drops to the floor with no resistance.

[adsgreen]

Is the clutch level with the brake pedal?

Mine wasn't by a slight bit and one of the Audi Techs said my pedal itself was broken up somewhere in the pedal box.
The explained the first part of "Free" travel before I felt resistance.

It might not be the same as mine, but worth getting it checked. Audi said that because of this free travel the clutch wasn't engaging/disengaging fully, which lead to sticky clutch and ultimately fubared the clutch.

Changing everything out again is just going to end up with the same result surely?

And you said yourself you had a light feeling at the start of the pedal stroke? And that your clutch pedal is not at the same height as the brake?

Regardless of what the mechanic has said, surely it needs to be changed out if only to rule it out?

Personally I would replace the clutch pedal assembly like Irishmike did in the above post keeping everything else as it is.

The clutch and flywheel is not pretty but plenty of material left and it will certainly last long enough for fault finding purposes.

If you find the new clutch pedal fixes the problem you can either run the second clutch until it dies or replace with a new one.

Good points there - if the pedal is screwed and not letting the clutch engage properly then it could overheat things like that.

[Surrey Sam]

I don't believe there is one definitive answer to this, mainly because it's not one simple symptom. It's very clear that there are a number of (sometimes subtly) different symptoms for different owners, and therefore different solutions. Some people have replaced the return pipe and all good, some people have replaced the entire assembly and all good, some people have tried both and still experience issues. The OP seems to have a new additional symptom (I've not heard of it before anyway), where the pedal drops to the floor with no resistance.

I'm kind of thinking along the same line.

My take on it though is that there's one initial problem that then gets ignored by owners hoping it will go away; the car may even get moved on because of this fault and inherited by the new owner and with this continual use the underlying problem causes excessive wear to the clutch, flywheel etc. I think the pedal box issue is down to the amount of times the pedal has been pulled back up by a foot - it could be worn or even bent.

The initial comment I made about there being 'no definitive answer' was really aimed towards the first fault, the rest is just a snowball effect from ignoring that first fault. Audi thought it was the return pipe and brought out a fix but was that really the crux of the matter?

[nikkak77]

Is the clutch level with the brake pedal?

Mine wasn't by a slight bit and one of the Audi Techs said my pedal itself was broken up somewhere in the pedal box.
The explained the first part of "Free" travel before I felt resistance.

It might not be the same as mine, but worth getting it checked. Audi said that because of this free travel the clutch wasn't engaging/disengaging fully, which lead to sticky clutch and ultimately fubared the clutch.

Changing everything out again is just going to end up with the same result surely?

And you said yourself you had a light feeling at the start of the pedal stroke? And that your clutch pedal is not at the same height as the brake?

Regardless of what the mechanic has said, surely it needs to be changed out if only to rule it out?

Personally I would replace the clutch pedal assembly like Irishmike did in the above post keeping everything else as it is.

The clutch and flywheel is not pretty but plenty of material left and it will certainly last long enough for fault finding purposes.

If you find the new clutch pedal fixes the problem you can either run the second clutch until it dies or replace with a new one.

Good points there - if the pedal is screwed and not letting the clutch engage properly then it could overheat things like that.

Thanks guys for the advice. Since everything is being replaced, I will replace the pedal assembly too.

As regards the scratches and grooves in the LOBA clutch and pressure plate, I got to say that they guys in Germany were very helpful to answer my questions. The thickness of my clutch disc is 8-8.1mm at the puks and the mint new is 8.3mm. The difference after 2.5k km is most likely my fault as i did not leave it to bed in for about 1000km as per the LOBA technician's guidelines earlier. IN any case , there does not seem to be a problem in this to put it back in.

Will keep you updated

[Scott Long]

Can't believe a definitive answer to this problem doesn't exist yet. Good luck and I hope the problem gets fixed for you.

http://www.audizine.com/forum/showthrea ... -RS4-Owner

Audi stock RS4 pressure plate is a self adjusting design, it was the cause of my problems. I have replaced clutch and pressure plate with a non adjusting design, and replaced slave cylinder and got a steel braided hydraulic line. Clutch in my car grabs hard and feels great.

Erm, sorry to sound like an ass, but I read your post on AZ: "Car has 109k on it, 1 owner, clean carfax, good maintenance records but original clutch". Original clutch after 109K?! I think I found the problem!

Even with 109k on my RS4 I would have thought clutch would last longer. My first Audi went almost 150k on oem clutch. I was hoping to get a few years of ownership before needing clutch replaced. But now I'm good for a while. I really want to buy JHM supercharger kit next summer so at least I have strong clutch.