Hybrid clutch issues

[v-lux]

Following on from my gearbox trouble thought i'd start a new thread for this clutch thing.

So, here's some pics i've taken of the various clutch parts with measurements etc.

Sachs friction plate


Guide tube on Sachs friction plate


LUK friction plate


Guide tube on LUK friction plate


LUK friction plate center base measurement


Guide tube from my wrecked box - note burred edge on the rim of the tube


Guide tube from a different vehicle that is just showing signs of wear on the end, also had a recent LUK friction plate


Guide tube from Jebiga41's van - showing signs of wear on the end of the guide tube.


Internal measurement of a guide tube



From what we can tell between a few of us it seems as though the dimensions of the center of various friction plates are quite different.
The problem - seems as though its well worth checking the friction plate center dimensions before you install a new friction plate, certainly on a hybrid clutch set up anyway. Need to check that the center of the friction plate's outside diameter is less than the inside diameter of the guide tube.

Failing to check this might very likely result in the same problem illustrated by the photo's above, which is the friction plate center rubbing on the guide tube.

Sachs friction plate seems to clear no problem at all.
An older LUK friction plate i had on my van a while ago clears no problem, but the newer one in the pictures above does not clear.
Another LUK plate fitted by Andy recently had an even larger center dimension (the same as the LUK base center measurement picture) which caused the clutch to not operate at all. (This was solved by grinding back the friction plate center to the dimensions of the Sachs one in the pics above)

This might be an issue with any brand of clutch (LUK, Sachs, Valeo, whatever) but worth checking the center dimensions.

We've also been theorising this could be the source of 'Gearbox Chatter' on vans that have had tdi's and/or hybrid clutches.........perhaps....?

[lloydy]

So is this only if you are mix and matching clutch parts? I have a golf 3 clutch and haven't felt any issues?

[v-lux]

As far as i know lloydy, there's no issues at all when using all the Tdi bits. The only ones that seem to be creating an issue is hybrid set ups. (ie VR6 and 2.1WBX hybrid set up)

[lloydy]

Ah ok, like I said earlier I have a jx input shaft if you need it

[syncropaddy]

As the 1Z flywheel / 2.1 WBX Centre Plate / VR6 Pressure Plate seems to be a popular combination would it be an idea to sticky this thread. The most important dimension here is the guide tube as its a constant, whereas the centre plate dimensions seem to be all over the place.

[HarryMann]

A very interesting observation Jeeves (Aidan? Al?)

Stickied for now anyway

[silverbullet]

While there's one out and on the bench...what's the bolt PCD and release bearing height for the VR6 cover? I'm looking for one that's interchangeable with the 2.1 wbx one for greater clamping force or are they completely different?

[joe75]

Interesting post.

I have been having gear selection issues post here https://club8090.co.uk/forum/viewtopic.p ... 7#p7807067 My issue is a intermittent gear selection problem. I am running a mTDI (AHU) on Syncro box.

After reading your post I went and had a measure.

My guide tube is the same as yours.


My friction plate is ...


There is no way my friction plate will go over the tube. Should it?


I think my problem is that my release bearing has been able to move too far and get caught on the tube. When I operated the clutch arm the bearing went along the guide tube and then jammed.


As I am trying to fix this once and for all should I be looking for a friction plate that fits inside the guide tube?

[v-lux]

Is there any wear on the end of the guide tube?

[joe75]

Is there any wear on the end of the guide tube?

The tube looks ok


The release bearing seems worn. The lip on the inside where the bearing runs up and down the tubes seems to have rubbed on the clutch pressure plate? I am going to replace the release bearing as I think it is the cause of my problem.


Upon reading the post again I am not sure if the clutch plate is meant to run inside the guide tube? There does not seem to be much metal sticking out?


As I never did the original set up I am kind of figuring this out as I go thanks to the help of people on these forums. After re-reading this post I am not sure I am using a hybrid clutch as the flywheel and clutch set up is for a AHU Passat engine, with the release bearing being a standard T3 one. I think in my case the bearing has caused the intermittent bad gear change. I also noted that when the bad gear change started i also got a lot of clutch judder in reverse, and at slow pull-aways?

[HarryMann]

I also noted that when the bad gear change started i also got a lot of clutch judder in reverse, and at slow pull-aways?

To Be Honest Joe... that is not uncommon. It may be relevant, but don't attribute too much significance to it..

With a wee bit of clutch bite, even with good engine mountings, it doesn't take much shimmy along the trans-line to develop into judder when reversing... just saying like

[Justavan]

Here is my 2 pence worth,

All the above problems I've come across before on various VW busses.

The one thing I have found that is often overlooked is the lever arm pushing the thrust bearing off centre to the gearbox shaft due to mix and match of parts over the years.

If the arc of the leaver arm is lifting the thrust bearing to high then all matter of problems develop which are often misunderstood such as juddering and stiff selector.

Like I said just 2 pence of info but might help out with a few clutch issues..........

[HarryMann]

Yes Eric
The only obvious way I can that happening, is if the face of pressure plate, the diaphragm, protrudes further aft than VW intended or the release bearing is a different thickness e.g. as you say, non standard clutch parts, non-standard flywheel etc. Then contact will be made with the arm at angle other than just prior to a right angle. I would have thought, design-wise, the arm should be at right angles and dead-centred as the full pressure starts to release the clutch, though I imagine this is not too critical since the bearing has a degree of float on the arm and the plate also a tolerance on the diaphragm.

[joe75]

Here is my 2 pence worth,

All the above problems I've come across before on various VW busses.

The one thing I have found that is often overlooked is the lever arm pushing the thrust bearing off centre to the gearbox shaft due to mix and match of parts over the years.

If the arc of the leaver arm is lifting the thrust bearing to high then all matter of problems develop which are often misunderstood such as juddering and stiff selector.

Like I said just 2 pence of info but might help out with a few clutch issues..........

From looking at my issues of bad gear selection and then the release bearing clips bent on one side I really think this is my problem. I won,t know for sure until it is all back together but in the mean time how can I stop it happening again? I really don't want to have to drop the box every ten thousand Kms!

[Justavan]

Yep there is nothing worse than finishing a repair or replacement task only to find things are not right.

Here is my thinking on your clutch issues.

The lever arm could be slightly bent or the fingers that hold the thrust bearing bent and not square in relation to the flywheel face.
The lever arm could have been replaced and the bearing fingers could have a longer or shorter stroke, hence the binding on the guide tube.
The needle bearing in the crank could be worn or missing.
The shaft bearing could be past its wear limit.
The slave cylinder push rod length, mounting bracket or fluid could all be slightly off, all resulting in your lever arm not starting at the correct stroke position.
The deck hight of your pressure plate might be wrong. The hight from the friction face to the bearing surface if to high will cause problems.
The friction plate itself should be checked for thickness and warping as just because it looks good or new don't mean its above giving problems.

In other words all the little things that separate the friction plate from the face of the flywheel all add up to give you a smooth judder free action.

You are trying to get the stroke of the thrust bearing when it is in its mid point of travel as close to right angle or 90 degrees between the gearbox shaft and friction face of the flywheel.
That way should get a even and smooth action without any lifting or dipping of the thrust bearing or fouling with being pushed to far.

Hope these above tips help you resolve your clutch issue and don't beat yourself up trying to get everything perfect as that is some times just not possible,,,,,,,,,,,