Author Topic: clutch plate dimensions  (Read 280 times)

0 Members and 1 Guest are viewing this topic.

Offline Tom K.

  • Newbie
  • *
  • Posts: 4
Re: clutch plate dimensions
« Reply #15 on: 11 March 2019, 17:44 »
Single solid plate:

Offline sb001

  • Sr. Member
  • ****
  • Posts: 378
Re: clutch plate dimensions
« Reply #16 on: 11 March 2019, 22:50 »
I could be wrong but I don't think any of the autostick clutch plates ever had the spring hub...
At least all the pictures I've ever seen of those show the single solid center plate like the one Tom posted above.


Offline Speedsterautoshift

  • Newbie
  • *
  • Posts: 32
Re: clutch plate dimensions
« Reply #17 on: 11 March 2019, 23:29 »
Oh whoops!!

I wish I could find a picture to post on here, I will make a great effort to do so, as my clutch plate is not like this as I suspect Volkenstein's is not like this one either.

So to my surprise that two different types of clutch can be used.

Mine has the friction material mounted onto thin plates which have a spring between them, so that as the clutch plate makes contact, the spring has to compress until everything gets to the point where drive is taken up.  These springs are very small and right on the outside of the clutch.

SB001, I know what you mean about a sprung hub, that is far more conventional and what I am used to. I think it is there to protect the driveline from too harsh letting in of the clutch, or maybe to smooth out vibrations from the engine to the gearbox, and /or vice versa.  Beefier springs in a circle around the hub, connecting the hub to the friction material bearing part of the clutch.  None of the clutch plates I have seen for the autoshift have these. I think this must be because there is no need due to the torque converter, but I am ready to be corrected.

Well I have spent ages trying to find a picture that shows this, but have failed.  I also note that on websites selling stuff for VWs there are generic pictures used and they do say this, but you have to notice it.  I didn't for a while.  However, with both sets of info, I think I am going to be able to get an overall picture of how thick the clutch plate should be, whether of one type or the other, unless the two pressure plates are different, of course.

Thanks again guys for all the info you have provided me with and I will let you all know how things progress. I am still kind of hoping that it is an assembly error, but in the end all that matters is to get it sorted.

regards
John

Offline sb001

  • Sr. Member
  • ****
  • Posts: 378
Re: clutch plate dimensions
« Reply #18 on: 13 March 2019, 19:43 »
John I would love to see a photo of this type clutch disc, I have never seen one like what you describe.

Offline Speedsterautoshift

  • Newbie
  • *
  • Posts: 32
Re: clutch plate dimensions
« Reply #19 on: 13 March 2019, 19:52 »
The garage owner took one of the edge of it on his phone, I am trying to get him to send it to me but his internet is a bit hit and miss.

Offline Speedsterautoshift

  • Newbie
  • *
  • Posts: 32
Re: clutch plate dimensions
« Reply #20 on: 15 March 2019, 17:01 »
Hi All,

SB001, Volkenstein and Tom K, here is the offending item as removed today by the garage, (yet another morning's labour to pay for.)

The image people have been asking for should tell you all you need to know, particularly the one taken of the edge showing the thin spring plates and the air gap. I think you will all be able to see that there are two types of clutch.   

There are also various things stamped into the plate, the curious 4 ^ 68, (the ^ is actually a tiny triangle), the vw logo in a circle and the letters "F & S" which may be a manufacturer.  If anyone knows the significance of these, maybe they could help me with this.

The overall total uncompressed thickness is 9.14 mm. The friction material is 3.2 mm each side, so maths tell me the plate minus friction material is 2.74mm. Bearing in mind that this includes an air gap this is interesting in itself. Overall thickness is 8.3 mm compressed by a clamp. so the air gap is .84 mm, and metal thickness is 1.9 so I guess there is possibly some slight error here (clamp over-compressing the spring plates compared to what would happen on the car perhaps), as I expect the thin plates of metal that make up the two leaves are 1 mm each, which would make more sense.

Volkenstein put the overall uncompressed thickness at 7 - 8.  Having spoken to the relining company, .1 of a mm can make all the difference so I would be grateful if you could measure the thickness of the lining material on the one you have with a calliper or a micrometer so that I can tell the company the exact thickness to fit, or machine the faces down to. I do not know if the thickness of the solid plate clutch is, or should be, comparable to the compressible plate, for instance do they both use the same pressure plate, I wonder?

Having reread the whole topic it would seem that friction material of 2.5 mm would be about right giving an overall thickness of 7.74 mm uncompressed or about 7 mm compressed.   This would also match the 7mm of the solid plate clutch that Tom K measured.

Let me know what you think and thanks again in advance.

John

Offline Speedsterautoshift

  • Newbie
  • *
  • Posts: 32
Re: clutch plate dimensions
« Reply #21 on: 15 March 2019, 17:08 »
Right, obviously did not manage to attach the images, I'll try again.

Offline Speedsterautoshift

  • Newbie
  • *
  • Posts: 32
Re: clutch plate dimensions
« Reply #22 on: 15 March 2019, 17:11 »
One more.

Offline Speedsterautoshift

  • Newbie
  • *
  • Posts: 32
Re: clutch plate dimensions
« Reply #23 on: 15 March 2019, 17:20 »
How DO you guys manage to post decent sized images, so you can see detail?  Wish I could, I'll try that last one one more time.

Offline Speedsterautoshift

  • Newbie
  • *
  • Posts: 32
Re: clutch plate dimensions
« Reply #24 on: 15 March 2019, 17:23 »
Well that one was just under the defined maximum image size yet is nowhere near as big to look at as the one of the clutch assembly further up in the post.  Really wish I could find out how to make the picture denser or less dense or something!

Cheers
John

Offline sb001

  • Sr. Member
  • ****
  • Posts: 378
Re: clutch plate dimensions
« Reply #25 on: 16 March 2019, 06:04 »
Hey John, just posted a test image below to check and make sure the image uploading was still working OK here. Not sure why you aren't able to post a larger image, the one I posted below was 120kB but if you click on it it still enlarges to a pretty decent size...

Anyway, are you pretty certain then that it is the clutch lining thickness causing your problem? What was the word on whether they had installed the release bearing correctly?
Also, F&S is indeed the manufacturer of that clutch plate-- that would be Fichtel and Sachs, they provided lots of various parts to VW in those days along with other German motor companies.

https://www.hemmings.com/blog/article/fichtel-sachs/
« Last Edit: 16 March 2019, 06:12 by sb001 »

Offline Speedsterautoshift

  • Newbie
  • *
  • Posts: 32
Re: clutch plate dimensions
« Reply #26 on: 16 March 2019, 10:38 »
Hi SB,
yeah, agree about the image, must ask a moderator.

I checked the fitting of the clutch plate, release bearing, pressure plate and forks etc.  The mechanic is very experienced with vans and other commercials that have pull clutches.  He got it absolutely right.  It was very interesting that the small star-headed bolts that hold the pressure plate were only just too short.  This would make sense if the clutch plate is overall too thick.

In fact it is more or less impossible to assemble it wrong.  The clutch plate cannot go in the wrong way round, if you leave the release bearing out it cannot be put in anywhere to do any good and assembling the whole caboodle onto the forked thing is quite simple anyway. In fact it goes together a lot simpler than many other pull clutches.

From the measurements that I have gleaned from members of this forum, it appears that a thickness of 2.5 mm per lining is about right, so I am sending it back to the company to have them machined back to that.

Thanks for your continued interest.  I will keep posting.

John

Offline sb001

  • Sr. Member
  • ****
  • Posts: 378
Re: clutch plate dimensions
« Reply #27 on: 16 March 2019, 11:15 »
Sounds like the clutch lining has to be the issue then... only thing left that makes sense.

Offline Speedsterautoshift

  • Newbie
  • *
  • Posts: 32
Re: clutch plate dimensions
« Reply #28 on: 17 March 2019, 00:33 »
SB001, did you see what I meant about the edge of the clutch plate being made up of thin spring leaves to which the friction material is riveted?  There is absolutely no doubt that the two sides of the clutch can be compressed together, thus reducing the overall thickness of the clutch by about 1 mm.

I am not massively experienced in the world of clutches but I have never before seen one like it, from that point of view.  I have to assume  that it is something to do with the way the clutch in these cars is actuated. As someone said, the clutch is either out or in, and I suppose if the solenoid operated valve is not set right then it might mitigate any rough clutching and declutching.

Anyway, it is all packaged up ready to be sent off on Monday.

regards

John

Offline sb001

  • Sr. Member
  • ****
  • Posts: 378
Re: clutch plate dimensions
« Reply #29 on: 17 March 2019, 10:58 »
Yep I understand what you mean now, those pics helped a lot. I initially thought you meant the "leaf" springs were around the edge on the surface of the disc but they are within the rim of the disc. Very unique. I guess all of the autostick clutch discs are that way, and I just couldn't see it from the angles the stock photos were taken by vendors selling them.