clutch plate dimensions

[Speedsterautoshift]

Since last post, Volkenstein, who has been moving house, has just got back in touch and has measured his clutch disc.  You can see it all if you look on the parts for sale forum under "desperately seeking a clutch disc".

I am taking his advice into account and will recontact the clutch reliners with a slight mod to the order, namely to go for 2.6 mm per side as opposed to the 2.5 mm mentioned originally. Even 2.7 mm would probably be OK.

Anyway, we will see.

All the best

John

[Tom K.]

Good idea - that clutch you have looks (and measures) too thick to me. 

[Speedsterautoshift]

Tom, and all, on talking to the clutch reliners yesterday I learnt that this type of clutch-plate is called a "fin" plate and the idea of the spring fins on which the lining material is mounted, is to ensure the clutch-plate makes even contact with the torque converter and the pressure plate.

Having thought about it, I would imagine a flywheel is much more solidly mounted to the rest of the crankshaft than a torque converter. By its very nature and the fact that it moves independently of the crank, via the fluid, there is more likely to be a bit of play, albeit it tiny, which could necessitate a way of distributing the clutch forces evenly across it, as well as ensuring the same thing with the pressure plate.

I am at the point now of thinking "how interesting" rather than "how annoying". Maybe you will be sharing my feelings!

[Speedsterautoshift]

Right.  The clutch has now reached the reliners and the bloke rang me today for a chat.  He says he has done "a bit of digging" and he has found a reference to a Fichtel & Sachs cltuch with linings 2.8 mm thick. He was unable to find an application and of course it had been discontinued. But we think this may well be the thing we needed to find.

So, this would give me an overall thickness between 8 and 8.5 mm, which looks ideal.

It will be a while as he has to keep sending it from Cleckheaton to their other workshop in Telford and then back, in order to make this, but we are going with it.
I'll keep you posted but we do now seem to be singing from the same hymn-sheet.

[68autobug]

I have heard that linings are available for the autostick clutch plate.... I thought maybe one of the standard vw clutch plates from a manual would fit the autostick.... It was too long ago to remember....

LEE 68autobug in Australia...

[Speedsterautoshift]

Lee, I don't think so, they are very thin and the re-liner doesn't know of any others so thin. I have searched all over the world for them, via the internet, with no luck. So 2.8 mm is what is going to be fitted and they are having to machine them specially. I suppose it may be possible to buy a 180 mm clutch plate for a manual, then machine the linings down to 2.8 mm. but this may well mean the rivets being on the surface.  The re liner said they were going to have to countersink the rivet holes deeper, then do the machining, as trying to do it other way round would not be possible. Of course being a fin clutch makes all this more complicated.

The process of making the linings, if they are already on a manual solid clutch would be possible I suppose, and the clutch plate could be useful to hold the linings in place while the rest of the work is going on. I have no turning experience but this may be an opportunity for someone with experience to chip in and tell us all how to do it, in case anyone else needs to know.  Now we seem to have nailed th actual thickness down.

[volkenstein]

Speedster,
              A manual 180 mm clutch plate is useless for an A-S clutch. I know - I measured one and played a lot. It essentially comes down to the clutch centrepieces being wildly different in terms off offset/depth/centre construction. I'll see if I can resurrect that threads pictures.


Volkenstein
Been there, done that.........

[Speedsterautoshift]

Hi Volkenstein, Hi Lee,
Please don't put yourself to any trouble over the manual clutch plate. It is absolutely obvious to me and the re-liners that these two  clutches are chalk and cheese.  The auto is fin and thin! It has no springs around the hub, the linings look like being 2.8 mm. The hubs were always bound to be different so this whole idea is an absolute non-starter. But thanks for having a look.

The real positive I am taking away from all this is, that if anyone else ever needs to replace their clutch plate, we will be able to tell them what thickness linings to get fitted.  I have literally just been rung by the re-liners and the chap explained that the rivets are stepped and it is more or less impossible to make them any thinner. Anyway, we had a bit of a discussion as to whether I am going to be charged again, I expect not but even if I am it is still way cheaper than paying for a "new" one from the suppliers, if you can find one.  They all want £200 plus carriage and and the old one to re-line, so you can see how much dosh they are making out of this!

Watch out for the end of this.

[Speedsterautoshift]

Hi All, this is an overnighter.
Time here is 1.00 am, and I am posting as the garage rang me yesterday to tell me that they have tried fitting the new clutch and the mechanic STILL cannot get the bolts to catch on their threads when he tries to bolt the pressure plate to the carrier. so he is still wondering what is going on.

What I need desperately from you guys who have dismantled and reassembled the clutch is this.  Is it the case that the bolts will not catch a thread and at least start by hand, or does pressure need to be applied to the pressure plate to push it in towards the carrier to enable the bolts to start?

If that is the case, then, fine, he will be able to do it.

But if it should be possible to at least start the bolts by hand, do you have any idea what he can be doing wrong?

I and the garage owner are both convinced that the clutch cannot now be too thick, but what worries both of us is that we might end up where we were after they last refitted the clutch. i.e . that the clutch will not disengage once the whole thing is back in the car.

We have agreed that if that happens I will just stick in in position 2, or one below top, start it and drive it home, but that is no solution to the problem, it just gets it out of his garage.

So, desperate again, for help and ideas.
Looking forwrd to reading your replies.

John

[68autobug]

Hi,
I thought I had an autostick clutch plate but when I looked it was a manual plate with the springs... My two spares are in the Gearboxes/transaxles... naturally... now I have had all Mine apart , many years ago... and I remember regreasing the clutch bearing in the gearbox I have in My car....  The major problem I had with mine after I had assembled it back together and in the car, was, I had undone the throwout bearing arm etc and had taken off the clutch arm on the top... and then I was trying to get the clutch to work... but I couldn't as I was trying to have the clutch throwout going the same way as the manuals, but ALAS , the autosticks go back to front...  they PULL the bearing, they do not push the bearing as in the manuals... it was all straight forward though... I am no Mechanic just self taught owner....   I showed the clutch to a mechanic, and He told Me straight away, that it pulls the bearing ..... but it doesn't seem to be your problem... unless the clutch facing is too thick>>!!! and not allowing it to go together?  I had no problems at all... but i was using all the original parts....  Do You have a Robert Bentley Manual for your car???
onpage 181 of My Manual, it shows the clutch plate, now there are small plates that are riveted to the linings and then these small metal plates are revitited with larger solid  steel rivets to the center plate itself... now these plates are located on the raised hub side....  but I wouldn't think that these would have been taken off...... So, I believe the LININGS are just too thick for Your clutch and the mechanic cannot bolt it back together because the clutch plate is too wide... Just how wide it can be.... I don't know.... I do remember a guy in the USA many years ago bought a new clutch plate as the old one looked worn out, but when He measured the new plate, the linings were exactly the same as the one in the car... ie.... there was no wear.... at all...   Now it seems that the too thick linings need to be taken back to the original size exactly.... maybe a lathe could do it....
The clutch plate does NOT WEAR in normal circumstances... It is either opened or closed... NO SLIPPAGE if it is set up properly....


Not good news I'm afraid....  do you have the measurements of the original clutch plate linings....??
Maybe the only thing to do, it purchase a complete autostick unit from a car that was still going before it was pulled apart.... I bought two of these, from cars that had little damage, one car was burnt out.... both from over 300 klms way....


cheers


Lee in Australia

[Speedsterautoshift]

Hi Lee

its 12.39 in the pm here you are probably in bed now!

The clutch reliners reckon it would be impossible to make it any thinner and I have to say I agree with them.
I know exactly what you are talking about as far as the clutch arm on the top of the gearbox is concerned.  There is a tiny dot on the end of the splined part that the arm goes over.

As far as I can tell from other posters who have measured their clutches, mine is now within tolerance.  you are right, it should not have worn, and it would not have done had the fitter set it up correctly in the first place.  It slipped a bit after the box was fitted, so we took it back and he adjusted it, but it then started slipping again so I tried to adjust it.  Not easy fitted to the Speedster.  But. like you, I did not appreciate it was a pull clutch, so probably adjusted it the wrong way.  Other factors are that 1/ it is fitted to a tuned 1800 engine which is far more powerful than the original, about 80 bhp, so the clutch is under more strain than usual and also, once it was all apart, there had been leakage and contamination of ATF, which didn't help.

But you seem to be saying that you didn't have to do anything special to get the bolts connecting the pressure plate to the carrier, and this is what bothers us all.

Sadly in the UK we tend to rely on Haynes manuals.  There are millions of them around and generally they are pretty good, especially for the older cars.  I have never seen a Bentley manual although I keep hearing about them.  The huge problem is that we are only doing this work to get the car sold.  Pat has fallen out of love with it.

What scares me is that we find it is something completely different which has somehow gone wrong.  To think I drove the damn thing into the garage, and the clutch worked perfectly!  We are all, me, the garage and the clutch reliners wishing like hell we had measured the unworn, uncontaminated side clutch lining, before sending it away.  Just never imagined they could get it wrong.
Lee, would the Bentley manual have a section on assembling and disassembling the clutch mechanism.  If so, would you be so good as to scan it and send it to me somehow.  I would need to be able to take it to the garage tomorrow, which is in 19 1/2 hours.

I have no idea if you can pm me through this site, if not please tell me and I'll send you my private email address.

That would be soooo helpful.

Many thanks

John

[Speedsterautoshift]

Lee, you mention buying another gearbox, they are sooooo rare in this country.  The one we bought had to be shipped over from the US.  so realistically, it is a non-starter.

To be honest, if we cannot get this to work, I think I will put the whole car back to manual, it will be easier to sell, we could have a higher final drive ratio, and an oil filter, all of which we lost with the conversion to autoshift.
what is annoying is that I told the mechanics to leave the three pedals there but they went ahead and fabricated a two pedal set, just like the original autoshift had.  We also left the old box etc with them, and these boxes are sought after now by people who want the IRS boxes for their camper vans.
Typical!

[68autobug]

Hi, I assume You are in the UK   they are fairly rare in Australia and probably VERY RARE nowadays... I was lucky to find two complete assemblies from Vehicle that were still being driven....  although both were about 350--400 klms from here...
As I bought both of them plus many other parts back 15-18 years ago...  Both these units would have been destroyed by now...  so You do not have the original 2 pedals either.... ??  YIKES.... Maybe the original clutch plate would have worked OK???

Problem is that these cars are now getting very old & very rare... &  worth many $$$$ in going condition...
You maybe able to find parts in other European countries where these cars were sold in some numbers....
Another problem in Australia, many of these cars were bought and the chassis used to make a manual beetle with IRS rear end.. as Australian Manual cars with torsion bar front end were NOT sold with IRS end in Australia... apart from a small number in 1976.....    So, even if these cars were still OK, they just used the chassis etc to obtain the IRS rear end from the auto stick semi automatic beetle... The hardest parts to find are the gear shifter plate, located under the gear shifter, the Flexplate, speedo, vacuum control valve, vacuum inlet manifold and the dual oil pump, as these parts were usually left on the body or chassis or engine.... when they were seperated...

Lee in Australia

[Speedsterautoshift]

Hi Lee, you seem to have missed my last post but one in which I asked you to scan and Pm me from your Bentley manual.  Would you mind having a read of it and seeing if you can help me?

The Autoshifts seem to have only been sold in numbers in the US, where so many people cannot drive a stick shift, apparently only about 5% can.

But please have a look at my longer post one above the last one.

[Speedsterautoshift]

Also people building trikes love them!  You can see why!