Clutch Problems: Causes, Symptoms & Repair (07-07-2004, 8:46)

Hello!

I've been experiencing clutch slippage when starting in first gear or reverse for quite some time.
You don't feel anything when starting in second gear.
Bleeding has always helped for months so far.

see:
/viewtopic.php?t=6016

But now I'm facing the problem that bleeding the brakes doesn't seem to be helping at all (I've already tried it with pressure applied to the brake fluid reservoir).

It's possible that the clutch itself is to blame.
I checked the engine mounts – I can rule those out.

The problem is: how do I figure out whether the hydraulic system or the clutch itself is faulty?

I hope you can help me.

Hello,

Please get in touch with MikeF.
Er meldet sich hier auch ab und zu (z. B. https://community.dieselschrauber.org/en/viewtopic.php?t=2934&highlight=).

He (or did he?) also had significant problems with clutch judder when starting.

Regards,

Rudi.

Thank you for the information!

I read his story the other day. Apparently, he's already on his fourth clutch and still hasn't found a solution to the problem.


I actually only have one important question:

Can the clutch judder be caused by the hydraulics?

Based on everything I've read so far: no.
Based on my own experience: it seems so!

Thought experiment:
Let's assume the clutch has a very slight defect. If there is absolutely no air in the hydraulic system, it can be engaged without any major problems. However, if there is even a small amount of air in the hydraulic system, the spring system (air, clutch spring) begins to resonate, leading to clutch judder. Bleeding the system provides a solution.
"However, the clutch is now more severely damaged and is already causing jerking on its own. Bleeding the clutch no longer helps (possibly because there is no more air to bleed out?)."

IMHO, that makes sense and aligns perfectly with my observations.

What does a clutch replacement even cost? 200 euros?

"Did you perhaps modify something at the front of the engine, near the timing chain cover? It needs to be removable for things like timing belt changes, etc. Is that part located opposite the alternator?"
I think it's important for starting. I also had it installed two weeks ago when I changed the clutch. And I think I'm experiencing slight clutch judder in second gear when I'm only briefly in first gear and driving uphill.

Best regards,

thomas
(who also owns the same car)

wolfi_b wrote:

However, if a small amount of air is present in the hydraulic system, the spring system (air, clutch spring) begins to resonate and this leads to clutch jerking.

I can hardly imagine that, because...

"You should be able to feel the pressure fluctuations in the hydraulic system as a pulsing sensation in the clutch pedal."

2. Based on my intuition, I believe that the oscillating masses in this system are so small and the spring constant of the likely air bubbles is so stiff that a significantly higher resonance frequency would result than what I recognize as the coupling jerks (~5 Hz).

Thank you for the answers!

thom wrote:

Did you perhaps do something to the front of the engine mount, because it needs to be aligned with the... example: when changing dental files, etc., is that thing located opposite the file?

Yes, I experienced that during the timing belt replacement. However, I believe I installed it correctly.
Yesterday, I also thoroughly checked the remaining engine mounts from underneath -> they are fine.

Ulf wrote:

I can hardly imagine that

You are destroying my beautiful theories...
But that actually makes perfect sense.


Yesterday, I noticed some engine oil leaking between the engine and the transmission. It could be a crankshaft seal, but it might also be from the recent oil change. I'm going to give the engine a wash.

So, in my opinion, the only things that could be the problem are the clutch and possibly the seal.

Hello!

I solved my problem .
I slipped the clutch while keeping the handbrake engaged (until it started to smell).
Seitdem funktioniert die Kupplung wei am 1. Hi!!!!!
I don't have an explanation for that (yet).
But a faulty crankshaft position sensor ring and oil on the clutch could be a possibility.

"Thank you for your help anyway!!"