G: Gearbox (Twin) Five Speed Gearbox, Clutch Shaft and Carrier

[andrew peters]

I have been putting a 5 speed gearbox in my Series C Rapide and I am keeping the stock clutch, I like it, it seems to work fine for me and in the past I've just assembled it without a lot of the the accuracy and detailed 'precise care' that probably should be achieved... I have made real and successful attempts to keep oil out though so I'm happy there... I will this time make more effort to set up my clutch better.. I've studied and thought extensively and I think I can achieve the perfect clutch that PCV intended! (my recent study guide is Les Goode, "clutch thy beast")
Anyway, my question to you experts out there...
The Surtees 5 speed appears to have the Series D clutch shaft, G3/1 with a shoulder (approx 5/16) between the spline and the clutch nuts fine thread, looks like a Series D style shaft to me (from looking at pictures) and my old G3 is different... Am I correct in thinking I should use the clutch shoe carrier C3/2, seal C18/2 and nut C20/1
I have ordered these parts just in case and I'm fairly sure I know the answer but I really would like some confirmation from someone who knows what they are talking about and I'm just 'guessing'
I'm sure the Series D method of sealing the oil out of the clutch is better than the Dowty seal but I will still machine a recess on the C3/2 for an O ring at the gearbox end, 'belt and braces'
On the subject of C3.. I put new seal PD24 and new bushes PD21 and PD25... the C3 seems a little tight with new seal, it's not the bushes... I hope that will ease up with use, I don't want a dragging clutch...the old worn parts sometime give a good service.
Another thing I thought I should replace, my kickstart shaft G83 was slightly bent and the spline slightly twisted, I put a new one in, as well as gearshift shaft G117 and G66/2AS... now my kickstart cover G1 is tight (misaligned?) and the shift lever doesn't return properly, like the shaft is binding a little... I guess all the worn out, tired and bent parts had learnt to live together in blissful harmony... Grrr! the fun of old bikes.
Once I get this all back together and working as it should, I may write a little 'blog' with some photos of my 'adventure', hopeful my anguished experience can be of use to others. My story will probably read as a collection of the knowledge of others before me but perhaps I can put it all in one place.
Thank you for the knowledge of those before us all!

 

[Bill Thomas]

It might be worth checking you have enough end float on the chain wheel,
After fitting the 2 bushes and seal,
The last one I did , The bushes were much too thick !.

 

[andrew peters]

I know this is not quite the right place to post this but I do seem to be having a lot of parts left over that I'm not going to need, other than obviously the complete 4 speed 'box, with a couple new gears. I have a lightened C3 and a brand new lightened G32, sorry Ken I just saw your post that you bought one from the Spares Co...

 

[andrew peters]

It might be worth checking you have enough end float on the chain wheel,
After fitting the 2 bushes and seal,
The last one I did , The bushes were much too thick !.

I haven't actually assembled it yet, let alone tightened a nut (I have a selection of shim washers) It just appears the seal is tight, I lube it and its better but the C3 is tight to push in, it turns ok but is certainly not loose, I'm sure this is ok, no oil can get past! Thank you for your input though, I will check when I'm 'torqued down'

 

[Robert Watson]

We found that when we went to all the effort to seal stray lubricant from finding its way around and amongst all the clutch and primary drive bits and pieces that we actually needed to very lightly oil the chain wheel bushings as there was nothing getting in there and it was as dry as a fire shovel......

 

[andrew peters]

We found that when we went to all the effort to seal stray lubricant from finding its way around and amongst all the clutch and primary drive bits and pieces that we actually needed to very lightly oil the chain wheel bushings as there was nothing getting in there and it was as dry as a fire shovel......

As I expected with those bushes, especially as I have renewed all the bushes and seals in there, the seal in the chain wheel does seem tight, which is a good thing I’d say..
Am I right about the series D C3 and C20 though? Maybe you don’t remember… I’m sure the shaft from Surtees is the series D style with the 5/16 of shoulder at the end of the spline.. I’ve ordered parts anyway but it would be reassuring to know I’m going in the right direction.. Tony would say I should’ve bought a D in the first place, personally, I think that bike is a baby only a mother could love though haha

 

[oexing]

When looking at the bushes in the chain wheel I think the design was not perfect from the beginning: Yes, oil is not wanted in the servo clutch, but then, both bushes would like reliable lubrication for minimal friction in there as you like to engage first gear with no offensive sounds . So by design the inner bush gets oil from the gearbox or primary. But then there is the seal - which should be not too tight on shaft - and the outer bush will be crying for oil but must run effectively dry for not oiling the servo clutch - somewhat unfortunate. Best have a multiplate and oiling is allright and wanted.

Vic

 

[andrew peters]

When looking at the bushes in the chain wheel I think the design was not perfect from the beginning: Yes, oil is not wanted in the servo clutch, but then, both bushes would like reliable lubrication for minimal friction in there as you like to engage first gear with no offensive sounds . So by design the inner bush gets oil from the gearbox or primary. But then there is the seal - which should be not too tight on shaft - and the outer bush will be crying for oil but must run effectively dry for not oiling the servo clutch - somewhat unfortunate. Best have a multiplate and oiling is allright and wanted.

Vic

I follow your comments with interest Vic, I wish I had your experience and skills, that you use so often, solving, even problems we never though we had, like the BMW style shift detent modification
Even though you seem to annoy, I think that may be the case, some here with your insistence to helicoil to metric threads!
However, despite my bike having many, many modifications to make the bike usable, rideable and reliable I am, for the moment committed to the Vincent clutch.. I have much time, effort and confidence in the design that I will persevere and boast of its virtues.. Thank you for your input,I agree with your comments on the bushes, they call it “self lubricating” but a lot is expected of those bushes, especially on the (hopefully) dry side

 

[Bill Thomas]

I haven't actually assembled it yet, let alone tightened a nut (I have a selection of shim washers) It just appears the seal is tight, I lube it and its better but the C3 is tight to push in, it turns ok but is certainly not loose, I'm sure this is ok, no oil can get past! Thank you for your input though, I will check when I'm 'torqued down'

All you need is a straight edge,
I don't think you can use shims here ?,
I would not want bushes too tight there,
But what do I know.

 

[greg brillus]

For the amount these bikes get used now, no need to stress.....these bikes have been going for years, although many of Vic's ideas seem good, we have no proof as of yet if they are actually any good........many a Vincent has clocked up many miles without the need to reinvent the wheel.......we all see the short falls, but it takes years of experiance in my view to come up with better solutions.........No offence Vic, im just not 100% convinced all your mods are worth the effort........only you and you alone have that sort fo time/effort to carry out these mods........I do the same and much more, but mostly for racing not on stock bikes........simply no need.