C: Clutch Clutch shaft seal

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highbury731

Well Known and Active Forum User
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I know this subject has been done to death, there are various patent solutions to oil migrating along the clutch shaft. Either an improved C18, or lots of gasket material on the splines, or a recess on the back of C3 clutch shoe carrier.
I had a look at the amount of metal present at the back of C3 (not very much), and also on PD24 clutch sprocket spacer. There's plenty of metal here for an O-ring groove. Then I noticed the rounded edge of the bearing E91 - there's room for a slim O-ring. So, I bought some 25mm x 1mm and also 25mm x 1.5mm O-rings, and a 1.5mm one fits between the bearing inner race and the spacer with a small push-back when you release the spacer. Definitely less than 0.010". Can anyone tell me if this will or will not work to cure oil migration into the clutch?
 
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oexing

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An o-ring just needs a minimal nip for sealing . But you have to check all faces for no scratches or rust craters, so no chance for the o-ring with these defects. You could polish that sort of flaws for a good seal, the geometry of these components is not a big factor for oil tightness. In conditions of very high pressures of oil or air o-rings will deform under pressure and seal just as well. At the clutch shaft there is no real pressure so no critical sealing job with o-rings.

Vic
 
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teunvandriel

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In the last few years, I dismantled the clutch maybe 10 times to degrease it, tried again and again with different types of sealant on the splines of the shoe carrier. Now tackling the ailment a bit bigger. Replaced all the seals, the 25-year-old PD25 and PD26 were both hard as stone. The original fragile C18/1 I replaced several times for a new one I never had much faith in. Friend Vincent Brake hopefully had a good idea for a better sealing of the shoe carrier, he made a bronze ring in it where the C20 presses against it. Meanwhile, I had also ordered a C18/1 and 2 from Maughan and although I didn't use it, this simple 2-piece ring (a 1/8" O ring) and an aluminium inner ring (see photo) looks a bit more reliable than the original C18/1 with the C18/2 modification. Furthermore, I smeared the threads of the C18 screws with Loctite 542, the heads of these screws with UNI Gasket, the splines of the C3 with UNI Gasket as well as the front of the C20, and smeared the threads of the C20 with Wellseal. Haven't driven hundreds of miles with it yet but the result is very satisfactory so far. It pulls the stones out of the street. But the future will tell.

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andrew peters

andrew peters

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A few years ago we machined this recess in the back of the clutch carrier for a 1 mm O ring.. The idea was from Norman (Timetraveller).. I believe it worked great for a many miles.. When I put the 5 speed 'box in my bike I had to change the carrier to the D style though so this C3 is surplus to requirements now.. The D Carrier was modded with the same recess, some people will say its not necessary of course with the O Ring on the C20 but us old guys often go with belt and braces... Oh, the D style O ring didn't work very well for me either actually... I, as others before, found a different O ring or combination of a couple different size O rings did the trick. One more thing.. the C3 is pretty difficult to hold in a lathe, because of its shape, so the recess is not an easy mod.. Norman hinted at that also...
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timetraveller

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The way that I did it, probably over fifty years ago was, that lacking machining skills and equipment. I used the 45 degree side of a valve seat grinding stone held in a pillar drill and just bored into the end of the shoe carrier. This left a vee shape in the end of the tube but it has never leaked or worn. With 'o' rings the quality and fit of the parts to be sealed is not super critical. I never get oil in the clutch, just dust. What Andrew has done is better but required significant machining skills.
 
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teunvandriel

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I just finished what might be the 10th clutch overhaul in the last 3 years. In the previous 9, the clutch was mainly cleaned with brake cleaner and some types of lubricants (Hylomar, Uni gasket, Loctite, Wellseal) were tried on the splines and threads and new original C18 was mounted a few times. In recent years I had already replaced the shoes and replaced the C24 new type clutch plate. I had also already made a perfectly working new C26 with a bearing in it.
This time (last week) ALL seals (PD24, PD26 and C18) replaced, and with that also the bronze bushes PD22 and PD24, the plates C23 smoothed with valve grinding paste. Unfortunately, the GENIUS TIP from Andrew and Norman (see above) came a week too late for me (WHY IS IT NOT IN THE VINCENT BOOKS?), I think Norman gave me the tip before, didn't understand it well then, but the picture above makes everything clear. At the moment the oil problem seems to me to be solved, hopefully for a long time, but if it comes back I will definitely use this tip.
 
andrew peters

andrew peters

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teunvandriel said:
I just finished what might be the 10th clutch overhaul in the last 3 years. In the previous 9, the clutch was mainly cleaned with brake cleaner and some types of lubricants (Hylomar, Uni gasket, Loctite, Wellseal) were tried on the splines and threads and new original C18 was mounted a few times. In recent years I had already replaced the shoes and replaced the C24 new type clutch plate. I had also already made a perfectly working new C26 with a bearing in it.
This time (last week) ALL seals (PD24, PD26 and C18) replaced, and with that also the bronze bushes PD22 and PD24, the plates C23 smoothed with valve grinding paste. Unfortunately, the GENIUS TIP from Andrew and Norman (see above) came a week too late for me (WHY IS IT NOT IN THE VINCENT BOOKS?), I think Norman gave me the tip before, didn't understand it well then, but the picture above makes everything clear. At the moment the oil problem seems to me to be solved, hopefully for a long time, but if it comes back I will definitely use this tip.
Click to expand...
Thank you for the credit, or part credit for the O ring mod but I have to give all the credit to Norman here for this tip and honestly a lot of tips over the years to improve our Vincents. I have the advantage over some owners in that I have access to very skilled machinists and welders etc.
Actually, the tip is in one of the Vincent books, (and MPH a few years back) "Into the Millenium" indexed under 'clutches'
I have to tell you all I am not a long term Vincent owner, in fact, less than 10 years.. However, what I decided to do when I started my ownership journey I accumulated books and Knowledge! Mostly from Vincent owners/riders and engineers cleverer than me. This I would advise to most people, several decades of experience are out there, and thanks a lot to this forum (big thanks to He/Him that cannot be named, I believe I have his pronouns correct Haha) for answering many questions, some stupid maybe but not to the poster (?)
Since I've owned my Rapide I've successfully put on quite a few miles and found the bike to be usable and reliable, able to keep up with modern traffic and capable of stopping and being seen by other road users, thanks to disc brakes, LED lighting and signals. I've been less concerned with originality than usability, there are enough stock bikes in collections and museums!
Don't be afraid to ask the 'elders' or read through the books and postings.. Most important.. Ride your Vincent!
 
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