Triumph 4 spring clutch (non cush type)

[kiwipom]

hi guys, just comparing the centre that John shows in his pic to my ones, his scroll goes the opposite way to S.R.Ms what do you think? cheers
Bob

[MG]

Yes, clearly a wrong one. It will pump the oil OUT of the chaincase, like a spiral conveyor. Just turn it by hand to see, direction CCW when looking at it from the splined side.

Better to send it back and get another one. I seem to remember that SRM has removed the centres from their online shop, saying that the taper wouldn't match the shaft exactly, so you got good chances to have problems there as well if it came from that faulty batch.

[alanp]

Yes, clearly a wrong one. It will pump the oil OUT of the chaincase, like a spiral conveyor. Just turn it by hand to see, direction CCW when looking at it from the splined side.

Better to send it back and get another one. I seem to remember that SRM has removed the centres from their online shop, saying that the taper wouldn't match the shaft exactly, so you got good chances to have problems there as well if it came from that faulty batch.

Yep, this wrong scroll situation gets me very upset - I bought a very expensive Tony Hayward belt drive for my A10 and it included an adaptor made for Tony by SRM with the wrong scroll, just like the photo. When I complained, SRM said it didn't really matter and supplied their 'Fix' which was a felt ring to fit between the rotating back of the adaptor and the stationary sealing plate on the face of the primary chaincase. Goodness knows how long that would last. Obviously because it would have cost them a lot of money to make another batch!! It's sad to see that they are still selling the adaptors with the wrong scroll even though they know they are wrong.
My expensive belt drive kit is still gathering dust on my garage floor while Tony says he doesn't know much about A10s and is relying on SRM who does!
It has taken the enjoyment out of my rebuild to be treated like this. If it gets replaced with a correct scroll one please let me know.
Alan 

[chaterlea25]

Hi Bob, Alan and All,
If you  look at the middle pic of my last post you can see that I said this one had the scroll going the wrong way
I got that one from Cake St Classics cheaply as he knew they were wrong
To the best of my knowledge these were supplied through Wassels (open to correction here)
(I also had problems with pattern 6 spring sleeves as they were undersize where the bearing race fits )

I have modified the "wrong " ones by machining off the scroll , Then I unrivit the centre from the sliding plate
Turn up a new one and rivit back in, but this time I incorporate a groove for a "Quad ring"
This is an X profile "O" ring used in Hydaulics
I use a cork gasket instead of the felt ring and wind up with a 100% seal 
The only thing is that it is then necessary to provide a breather for the primary case,
I have attached a brake pipe with banjo fitting to the filler plug on mu own SR but there are several ways of providing a breather hole

HTH
John O R

[kiwipom]

hi guys/John, thanks for the info, yes the only difference is that 55 quid+8quid post is not a cheap item. I have e-mailed S.R.M. and asked nicely for their advice but unless they offer to send a new one i will be making my own suggestions. I can`t understand how this problem can happen, no scroll at all would be better that one that works opposite to intended action. I thought that turning off the scroll and making a better seal that the origonal would be the way to go but i dont do my own machining and after paying good money i shouldn,t have to.Your fix sounds good and what you seem to be saying is that the primary case breath`s through that sliding seal so when a 100% seal is in place another breather would have to be made.
As a matter of interest being an expat Brit, we often answer the native kiwis who complain about british made goods that they say is useless with the saying of, yes we know it`s useless that`s why we sent it to N.Z. It seams we may have been telling the truth all along, cheers
Bob

[chaterlea25]

Hi Bob,
Yes, When the sliding plate side is "sealed" pressure builds up as the cases heat,
I have the mod done on my own SR for nearly 10 years no probs

HTH
John O R     (Southern Ireland)

[kiwipom]

hi guys, i sent an e-mail to S.R.M. about the faulty clutch centre asking them to replace it with a good one here is the reply,cheers, Bob.

The BSA A10 clutch centre whether with or without a scroll will not seal, the centres BSA`s and ours are 1.500 inch diameter, the hole in the sliding plates are 1.550 and can vary a fair bit above this.
No way does this constitute a "sealing" fit and will pass oil regardless of what shaft is fitted. Our centres are sent out with a felt washer to sandwich between the flange at the back and the sliding plate, this is the best way to seal up this area without totally redesigning the sliding plate system.
 
We have used our centres on bikes here with the felt seal with great success, please try , if you are not satisfied with the result, please return the item for a refund.
 
Regards Gary

[wilko]

They do have a good point.

[kiwipom]

hi guys, so why do they put the scroll on backwards?
Bob

[Hubie]

I had some trouble making this area oil tight as well.  In the end, I took the primary apart, had the scroll/worm/thread bit machined off the clutch centre and took the sliding plate and centre to a bearing place and they found an oil seal to suit.  I pressed this into the sliding plate and the problem is now solved.

Cheers,
Dave.

[alanp]

hi guys, so why do they put the scroll on backwards?
Bob

It's because when they have the part in a lathe with the top of the part rotating towards you as usual, it is easy to run the tool from right to left. It saves them having a more difficult job running the tool from left to right starting close to the flange. Laziness.
I see that SRM came up with the same excuse I got which is complete bulls**t.
Alan 

[alanp]

Attached are photos of the incorrectly threaded and my corrected clutch adapter. It now has a LH thread. The machinist used a diamond tipped tool to remove the hardened surface and fitted an interference fit stainless sleeve with the LH thread.

[MG]

 
Good man!

If it was laziness that made them cut it the wrong way 'round, why did they bother to cut one at all? Better to have no grooves than incorrect ones I reckon. Some people....