C: Clutch Refreshing Vincent Twin Clutch seals and pieces

timetraveller

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Also see page 139 of 'Into the Millennium' to see a picture of the mod I described earlier. Note that this can be done which ever type of main shaft and nut you have and totally does away with any need to seal the outer end of the shaft.
 

Robert Watson

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It's just a piece of steel with an ID that is an easy slide fit over the splined shaft and on OD just under the size of the shoe carrier, about 2 in long with a nice polish and bit of a taper on the end so it slides gently into the seal. Pull the shoe carrier out, push the piece in, no worries about the splines damaging the seal.
 

Peter Holmes

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OK, rather than putting information on the forum that I believe to be correct as opposed to knowing that I am correct, I made a call to Steve at Maughan and Sons, the clutch seal modification for B + C series Vincent twins is still available, it is possible that when this mod was done by them they might have cleaned the face of the C20 on a lathe to give a smooth surface for the O ring to mate with, this would not have been done to intentionally dimensionally change the length of the C20, but it is possible that in doing so the C20 does in fact become unusable if you want to revert to the C18/1 bonded seal, so in essence Hugo you were correct, in the past I have got round the problem of a too short C20 by having a little material turned off the thickness off the flange, enough to accommodate a decent thickness C19 shim without locking up the clutch centre, alternatively buy a new C20 from Maughan and Son, they are a thing of beauty, almost to good to put a spanner on.
 

craig

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Here is my collection of C20/1, C20 installed by previous owner (who was a machinist) and current available C18 type seals.
The C20 nuts vary in length with the new C20/1 nut being 0.050" longer.
Probably the C18 I have pictured as C18 might be C18/1 old style.

So what is the story with this new C18/3 replacing C18/1?

ClutchC20SealNutsA.jpg

ClutchC20SealNutsB.jpg



The C20/1 labeled here is incorrectly labeled, altho it came new in a bag labeled as C20/1.
I believe the unlabeled clutch nut is actually a C20/1 as it is shorter and cut back to allow a change to G3/1.
 
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Hugo Myatt

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OK, rather than putting information on the forum that I believe to be correct as opposed to knowing that I am correct, I made a call to Steve at Maughan and Sons, the clutch seal modification for B + C series Vincent twins is still available, it is possible that when this mod was done by them they might have cleaned the face of the C20 on a lathe to give a smooth surface for the O ring to mate with, this would not have been done to intentionally dimensionally change the length of the C20, but it is possible that in doing so the C20 does in fact become unusable if you want to revert to the C18/1 bonded seal, so in essence Hugo you were correct, in the past I have got round the problem of a too short C20 by having a little material turned off the thickness off the flange, enough to accommodate a decent thickness C19 shim without locking up the clutch centre, alternatively buy a new C20 from Maughan and Son, they are a thing of beauty, almost to good to put a spanner on.

My turn to eat humble pie. Memory is a tricksy beast. In my original post I refered to the seal as C19. It is of course C18 or C18/1. C19 being the shim. How or why I did this I have no idea. Apologies for the confusion.
 

craig

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So this new seal C18/3 with aluminum spacer to slip on G3 and the oring to go to the outside of the new C18/3 spacer would appear as my out of scale rough drawing?

The theory being that oil would not leak down the C20 threads?
maybe thread sealant?
Looks like a good design. Anyone successfully using C18/3?
This C18/3 seal also allows me to ignore the C3 mod, which I think is a good design as well.


ClutchSeals3C20bLarge2.jpg
 
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craig

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Also see page 139 of 'Into the Millennium' to see a picture of the mod I described earlier. Note that this can be done which ever type of main shaft and nut you have and totally does away with any need to seal the outer end of the shaft.
What issue of MPH is this mod described please?
i dont have this book yet , altho i have , it seems, hundreds of Vincent books.
Thanks
Craig
 

timetraveller

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Try 747 page 12. I'm lifting that information from the book without going back and checking. The mod is simpler than any of the others and can be done with the use of hand tools if machine tools are not available. The first time I did this, which is probably over 60 years ago, I did it by hand using a small grinding stone in a hand drill. This made a 'vee' in the inside of the tube to take the 'O' ring. Nowadays one would use a lathe, milling machine or whatever. Note that the 'O' ring only needs 10 to 15 thou nip to make it completely oil tight.
 

stumpy lord

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So this new seal C18/3 with aluminum spacer to slip on G3 and the oring to go to the outside of the new C18/3 spacer would appear as my out of scale rough drawing?

The theory being that oil would not leak down the C20 threads?
maybe thread sealant?
Looks like a good design. Anyone successfully using C18/3?
This C18/3 seal also allows me to ignore the C3 mod, which I think is a good design as well.


View attachment 25326
I have been using the C18/3 mod for many years, probably forty by now although it didn't have a number then , being supplied by the late Tony Maughn. It is easy to fit, and does work, no need for that horribly bodge of gasket cement on the splines.
A tip for the newer member's , if your clutch squeals on take up it usually means your main linings' are soaked in oil
 

craig

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i ordered and received a G3MOD to add to a standard G3 gearbox main shaft to turn it into a G3/1.
I thought I would assemble all the pieces and evaluate some time soon.
Merry Christmas
Craig
20181224_G3mod.jpg
 
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