C: Clutch Play in the Clutch Carrier Plate

[Chris-T]

Hi Folks

I have just started to reassemble the clutch on my Rapide and have found that there is, what I think, is a lot of end play in the clutch carrier plate, C13 as it slides on the clutch retaining nut, C20. I have checked to see that the seal is fitted correctly and when tightened the C20 fits into the seal recess in the shoe carrier, C3 which it does, just, so I’m sure that everything beds down as it should.

When I took the clutch apart the oil sealing was done by a thin copper washer however I have replaced this with a Dowty seal C18/1, the seal being thicker than the copper washer, which gives me end play which amounts to about 0.079” without the C19 shim washer fitted.

I cannot find any reference in the books on how to shim this out therefore I assume the components to be machined so that this is unnecessary. I am presuming here that there should be minimal end play as otherwise shim washers would be unnecessary. I can easily shim the play out but this doesn’t seem to be right. Has any body else had this problem and have they any ideas as to what is going on here.

 

[stumpy lord]

Hi Folks

I have just started to reassemble the clutch on my Rapide and have found that there is, what I think, is a lot of end play in the clutch carrier plate, C13 as it slides on the clutch retaining nut, C20. I have checked to see that the seal is fitted correctly and when tightened the C20 fits into the seal recess in the shoe carrier, C3 which it does, just, so I’m sure that everything beds down as it should.

When I took the clutch apart the oil sealing was done by a thin copper washer however I have replaced this with a Dowty seal C18/1, the seal being thicker than the copper washer, which gives me end play which amounts to about 0.079” without the C19 shim washer fitted.

I cannot find any reference in the books on how to shim this out therefore I assume the components to be machined so that this is unnecessary. I am presuming here that there should be minimal end play as otherwise shim washers would be unnecessary. I can easily shim the play out but this doesn’t seem to be right. Has any body else had this problem and have they any ideas as to what is going on here.

Hi,
with every thing snugged down tight, the end float on the carrier PLATE C13 should be about 0,010". more than that means loss of lift on the primary clutch plates. that's why you have A C19 shim.

 

[chankly bore]

Old Speedway rider in OZ says .006", not that it is critical, Funny, he's used the standard clutch for over 40 years and had no trouble- duz make yer fink a bit, dunnit?

 

[Chris-T]

Hi,
with every thing snugged down tight, the end float on the carrier PLATE C13 should be about 0,010". more than that means loss of lift on the primary clutch plates. that's why you have A C19 shim.

Thanks for your reply, the clearance you mention is sort of what I expected however the shim is 0.030" which leaves 0.049" play. Is it normal to put in multiple shims in to reduce the clearance? 2 shims still leaves 0.019", still more than 0.010". This doesn't seem right to me hence the original query.

 

[greg brillus]

Probably from a miss match of parts now that you have a dowty seal in there, the nut is now further out than it should be. I would leave the dowty seal out and use a small bead of sealant on the inner vertical face of the nut so the sealant/nut comes up against the face of the shoe carrier. The plate carrier should have around 0.010" clearance any more is not necessary but don't go the other way and make it too tight either.

 

[timetraveller]

Sorry if I get on to one of my hobby horses here but this part of Vincent design can be improved. The original idea of smothering the gearbox main shaft in sealant in order to stop oil getting into the clutch is inelegant while the unfortunate original seal was inadequate. With the change to the 'D's the end of the main shaft was modified as was the nut, C20, which was an improvement but still not perfect. Machine a small recess at the inner end of the shoe carrier shaft so that an 'o' ring can be fitted inside the end where it buts up against the input to the gearbox. An 'o' ring here only needs about a five thou nip to make it oil tight and this completely stops oil migrating along the main shaft into the clutch. Then one can leave out all types of seal at the clutch end and just get on with adjusting clearances. With this mod one gets dust in the clutch, not oil and when the time comes to remove the clutch for some reason it just slides off the gear box main shaft. One does not have to break the solidified sealing compound.

 

[roy the mechanic]

Furness + Searle did the "o" ring mod on mine, not only get dust, gets rusty too. On re assembly I put just a smear of hylomar in the recess to ensure the ring stays put.

 

[Peter Holmes]

What equipment would I need to do this mod, sadly Furness and Seattle are not an option, any offers/suggestions on who could do this for me.

 

[Marcus Bowden]

Come and visit me Peter my handsome, you know what equipment I have and the heavier stuff is down the road in Harvey's toy shed.
bananaman

 

[timetraveller]

That is a kind offer from Marcus but if you find it too far to go I can now reveal the way that I did it, nearly 60 years ago. Without access to a lathe, or the skills to use one, I used a small grind stone, the kind and size that one uses to put double backlash onto the two top gears for racing, and ground a shallow 'V' all round the inner face of the end of the shoe carrier. I made the 'V' deep enough that the 'o' ring would be compressed inwards and allow the end of the splined part of the shaft to bottom out on the spacer at the input to the gearbox. It has lasted for years and never given any trouble. Of course machining a recess would be a 'proper job'. The confessions of a once young man