Clutch Slipping After 7k Miles: Why?

Hello everyone!
Sagt mal was kann da los sein. Ich hatte ja bei km 12000 eine komplett neuen Kupplungssatz für meinen Passat Variant 96kW TDI PD Variant bekommen. Grund war ein Rupfen die ersten paar min. nach dem Kaltstart ab 7tkm. Bei warmen Motor war fast nichts davon zu spüren. Ich hatte die Kuplung und den Schwung damals selbst gesehen. Es waren punktfürmige Abdrücke am Schwung zu sehen und der Schwung schlug in eine Richtung hart an, in die andere Richtung dämpfte er weich. Begonnen hat das ganze ca. bei km 5000. Jetzt scheint es so daß das ganze wieder beginnt. Ist aber so, daß bei kalter Kupplung weniger zu spüren ist aber dafür bei warmer mehr. Spürbar ist aber im Prinzip fast immer! Mal mehr mal weniger. Speziell wenn es sehr heiß ist dann ruckelt (rupft) die Kupplung beim Anfahren. Jetzt weiß ich nicht mehr weiter. Warum ist das so? Oder könnten das die Motorlager sein, die laut ein paar Zeitschriften ja SEHR WEICH ausgelegt sind und dadurch das Auto zum Ruckeln neigt. Interessant ist daß es jetzt wieder bei ziemlich gleicher km-Leistung auftritt. Also muß es eine andere Ursache haben warum die Kupplung dadurch immer 'ruiniert' wird. Also eines ist sicher: an meiner Fahrweise liegt es sicher nicht! Es gibt nur 2 Möglichkeiten: entweder gibt es schlechte Kupplungen und ich habe bei beiden ein Pech gehabt, oder was anders ruiniert mir immer nach gleicher km-Leistung die Kupplung. Oh, and one more thing: apparently, everything was swapped out back then, including the clutch release bearing!
Note: The clutch doesn't make any other noises, and everything else seems normal except that the transmission slightly 'jumps' when shifting from 2nd to 3rd gear. When I got the new clutch, everything worked perfectly, but unfortunately, only until now . The replacement was done at 12,000 km, and the current mileage is 20,000 km. The 'jerking' started again around 18,000 km. This can't be a coincidence?!?! Or are there really bad batches of clutches? What should I pay attention to during the next replacement, and what should I tell the workshop? I was thinking about a complete hydraulic bearing replacement for the engine and transmission, clutch (check the production date), release bearing, centering sleeves between the transmission and engine, and possibly the clutch cylinder. Does anyone have any other tips? Or does anyone else experience a slight 'jerking' when starting, especially now in the summer with high temperatures?

Greetings.

Hello,
'I had a similar problem with my Polo about 10 years ago. Back then, it was caused by a leaky crankshaft seal that allowed oil to enter the clutch area. Eventually, the viscosity of the oil comes into play, and the friction material suddenly sticks to the disc. This is what causes that 'jerking' sensation.'
Perhaps something like that still happens today. If they haven't replaced your shaft seal, the new clutch won't last long. And with a minimal leak, you might not even notice the oil seal is failing.
Was the clutch slippery?

Regards,
Eike.

hello,
Does your car perhaps have a dual-mass flywheel? Could the problem be related to that? These components are only supposed to have a small amount of play, so maybe someone here knows more about them and can enlighten both of us.
Best of luck going forward.

Hello!
No oil leaks were visible, and the clutch was dry! Apparently, the pressure plate and bearing weren't replaced after all. What should I do? Things are starting to become a problem again.
Yes, the new Passat has a torsional vibration damper (ZMS) wheel. The old flywheel only provided soft damping in one direction; it was very rigid in the other. In a textbook, I found the following potential sources of error:
Damaged engine/transmission mount.
The gearbox is not securely mounted in its housing.
Printing plate is not distributing ink evenly.
Takeaway disc, not an original part.
The crankshaft does not align with the transmission shaft.
The latch is only releasing on one side.

I'm sure I can convince my mechanic to do all the replacements, but what about the issue 'crankshaft doesn't align with the transmission shaft'? The suggested solution is: 'Check the alignment surfaces of the engine and transmission.' How is that supposed to work? And what if it doesn't fit?

Greetings.

Hi,

Quote:

I'm sure I can convince my mechanic to replace all of this for me, but what about the point "crankshaft does not align with transmission shaft"??? The suggested solution is: "Check the alignment surfaces of the engine and transmission." How is that supposed to work? And what if it doesn't fit???

Regarding the clutch pressure plate retaining sleeves... if they were forgotten at the factory, they should have been noticed during the first clutch replacement at the latest.

Best regards, Rainer.

Hello!
I just went to the mechanic. He looked at it but couldn't find anything or didn't want to feel anything. It's true that, like always (the observer effect), it was less noticeable at THAT moment. But it *was* noticeable! I then tried to hold the point where the clutch engages abruptly. The mechanic commented: 'Do you always keep the clutch engaged for so long?' Well, I explained to him that I only did that as a demonstration to generally show how it feels. He understood then.
He's now asking if this is a common issue, because his statement was that everything was supposedly replaced back then, and a clutch naturally 'changes' over time, becoming 'harder' and 'rougher.' Let's see what comes of this situation.
Bezüglich Paßhülsen hat er gesagt, daß die 'nur' zum Zentrieren sind damit die Schrauben leichter reingehen. Der Flansch am Motor und Getriebe ändert sich dadurch nicht und man kann somit auch die Fluchtung NICHT arretieren! Ist ALLES gegeben! Na ssuper!

I'm feeling quite desperate right now!

Greetings.

Sure, here is the translation of the text from German to English:

"Hi,"
Regarding the cartridge cases, the expert is mistaken. Although that doesn't mean he'll suddenly fall from the sky...

Hello!
And what about the sleeves? Are they also responsible for longitudinal centering???

Greetings.

Hello,

They ensure that the crankshaft and gearbox shaft are aligned.

Best regards, Rainer.

Hi,
I was told that the transmission housing and motor flange are completely screwed together anyway, regardless of whether or not spacer bushings are used. He's probably right about that, isn't he?

Greetings.

MikeF wrote:

Hi, I was told that the transmission housing and motor flange are completely screwed together anyway, regardless of whether or not spacer bushings are used. He's probably right about that, isn't he? Greetings

"Threads not centered" is the principle. Threads inevitably have some play. This only matters in simple cases.