Lockdown clutch troubles

Guys,

I need a bit of advice.
Just got back to my house in france after 3 months in the UK looking after parents and started the old bird up (1996 Audi A4 1.9tdi AFN engine), well happy as it went first flick of the key but it wont go in gear as the clutch wont engage/disengage.

Start it in 1st and use the revs to pick a slot and it rolls through all 5 gears fine without the clutch pedal down.

The pedal feels ok (but I haven't driven it for 3 months so I may be wrong here), no fluid round the slave cylinder and ive also rebled the slave just in case it had a bit of air in but nothing makes any difference.

Any ideas?
Ive never had a slave go on one of these so not sure how they fail but I would have thought you would see some fluid somewhere if it had.

TIA

forgot to mention, its had a new clutch 6 months back (I fitted it so know it was definitely done) and since then ive done roughly 2000miles

any strange noises? can you get an inspection cam and look at the clutch? your master might be internally bypassing. which happens. might have to rebuild that too.

No strange noises coming from anywhere when its running and you press the clutch.

Ive just popped the slave out to have a look and cant see any fluid from the inner rubber boot but I have noticed that it is really easy to push the slave cylinder rod back into the body. (not sure if that's normal for one of these)

Stevie Tease said:

No strange noises coming from anywhere when its running and you press the clutch.

Ive just popped the slave out to have a look and cant see any fluid from the inner rubber boot but I have noticed that it is really easy to push the slave cylinder rod back into the body. (not sure if that's normal for one of these)

Click to expand...

might be time to get new master and slave. one or both are internally bypassing. like a brake master cylinder. sometimes they will bleed out fine but will not actually build pressure. the seals internally do fail. Which it may have been weak before the clutch change. But now with the extra force required to overcome the new pressure plate, causing a worn internal seal to blow out.

to test you can have someone lightly push the clutch. you should not be able to move the slave by hand with the clutch depressed. did you happen to change the oil in the clitch system?

With the clutch slave removed, how far is the clutch lever in from the slave mounting surface on the bell housing before you feel resistance? It should be around an inch.

Is this a single mass flywheel set up? A Sachs by any chance?

It's also possible that after sitting for 3 months (in particular if there's been lots of rain or other high humidity) the clutch splines are binding on the transmission input shaft. When this happens the clutch pedal feels normal.. 'cause it is... but the clutch disk itself isn't moving and thus not able to assist in gear shifting.

If this is the case sometimes it will break free on its own as it vibrates a bit, is rocked a bit by accelerating/decelerating abrubtly, and/or the clutch pedal is snapped back multiple times... but sometimes the tranny has to come out to free it up.

Had this happen to me once so far... I had forgotten to lightly lube the splines during a clutch job on a vehicle only used during the summer. Never made that mistake again.

So ive had a glamourous assistant (well an assistant anyhow!) press the pedal whilst I held the slave and its mega strong. Not a chance on pushing it back in when the pedal is pushed.

I didn't change the oil when the new clutch went in but it 2 months prior I did a full fluid change so it should have been good and is still looking clear when I tried bleeding today.

Single mass flywheel and If I remember it was a sachs plate, and id say I have roughly an inch and a half before you feel resistance on the lever.

Just reading through a few old thread and there are quite a few tails of sudden and unexplained plate failures with no prior symptoms.....

if your hydraulics are working right. id say something with the clutch went. can you borrow or rent an inspection camera? Also there is a spec somewhere that states how far the slave extends when the clutch is depressed. Your master could still be bad. always make sure of the easier fixes first. I would still suspect the hydraulic system first.

Throw out bearing has probably rusted on to the transmission output shaft nose cone and won’t slide

Since I can’t look at it myself, I should say possibly, not probably

Stevie Tease said:

So ive had a glamourous assistant (well an assistant anyhow!) press the pedal whilst I held the slave and its mega strong. Not a chance on pushing it back in when the pedal is pushed.

I didn't change the oil when the new clutch went in but it 2 months prior I did a full fluid change so it should have been good and is still looking clear when I tried bleeding today.

Single mass flywheel and If I remember it was a sachs plate, and id say I have roughly an inch and a half before you feel resistance on the lever.

Just reading through a few old thread and there are quite a few tails of sudden and unexplained plate failures with no prior symptoms.....

Click to expand...

Yeah, I take it you've run into the thread where the issue is that the wire ring that serves as the pivot for the finger springs on the pressure plate snaps at the weld and it gets displaced. You can press on the lever and without the pivot there it is not going to release the clutch. I've found it to happened a couple time in my experience and so have others on this forum.
It would require pulling the trans out and inspecting the inner side of the PP. I will see about a pic or two when I get a chance.

inside of the Sachs pressure plate



pivot wire and weld - note that this one is not broken; I'm just illustrating where the trouble can happen.

Cheers for all the reply and pics guys,
Work got in the way so im back on it tomorrow.

Im thinking everythings pointing towards an internal prob so im going to pop the slave cylinder back out tomorrow and see if I can rig something up to manually depress the lever fully (not sure if anyones done this before and can give a heads up on how they did it?) then start the car with the wheels on the deck and if I can get the gears all silky smooth like then its gotta be on the hydraulic side in my mind.

If not ill drop the tranny.

Yup, once you confirm the slave is OK the tranny has to come out no matter what it actually is.

Right so nothing I tried worked so today I got the gearbox out and found that the friction plate had proper welded itself to both the flywheel and the pressure plate.
So much so that once I had prised it off the flywheel I needed a hammer and chisel to get the friction off the pressure plate!

I was sure it had a single conversion on this but its a definitely a dual mass.

Obviously I need to replace the clutch but im thinking on doing the solid flywheel conversion.

Whats the benefits of doing so?