C: Clutch C45 Clutch Nut Lock Spring

Bill Thomas

Well Known and Active Forum User
VOC Member
I would be more worried about a worn out washer E76,
If the Nut has been loose the washer spins and wears out,
Letting 4 th gear not to be in full mesh with the double gear,
We did Terry Wordinghams and found just a tiny ring , In stead of a washer,
The ring was so hard to see, Somebody fitted a new E76,
But the Bike was not run till we got hold of it !,
Which took all the free play out of the main shaft,
Lucky I always give the shaft a push pull , And found NO play !, So we stripped it out.

Love posting Trev's gearbox photo !.
 

Attachments

  • 29AED7E7-3CF8-4DCE-82BE-E7C54341FC13.jpeg
    29AED7E7-3CF8-4DCE-82BE-E7C54341FC13.jpeg
    121.7 KB · Views: 22

Peter Holmes

Well Known and Active Forum User
VOC Member
I always run with a magnetic drain plug fitted, it is great for checking for ferrous metal debris, I am sure that if a washer had eaten itself away I would know, and my gears selection and continuous engagement is also very good, the only real problem I have is engaging first gear on an uphill incline, but that problem is a well known by product of the Grossett electric start sprag clutch.
 
Last edited:

Peter Holmes

Well Known and Active Forum User
VOC Member
For not the first time in my years of Vincent ownership I have suffered failure of the C45 locking tang, self evident when the C20 clutch retaining nut unscrews itself and the handlebar clutch lever gradually ceases to disengage the clutch, this normally happens at the most inconvenient time and place, the time before yesterday in the middle of Dartmoor, thankfully yesterday it occurred very close to home, it is in reality a fairly easy fix, even at the side of the road, if you have the required tools and a spare spring, even if you don't have a spring you can simply bend another tang onto the old spring to get you out of trouble. (thanks for the tip Marcus)

But why does this happen repeatedly, am I the only person this happens to, I try to always use a new replacement Club Spares spring, I always do the C20 nut up FT, always to next available slot, no matter how hard it is to get it there, I never back off to the previous slot, the spring always breaks at the weakest point, on the 90 degree bend, my question is, is there a better engineering solution than the one currently used, other than resorting to one of the Loctite products, has anyone managed to make a flat plate key to lock the two slots rather than the rather flimsy spring, and if so how have they retained the key to keep it in place.

I now carry a spare spring and tools to carry out a roadside repair, but I don't really think it should ever be necessary if there was a decent engineering solution to locking the C20 nut in position.
So this is my solution (I hope) it is a key made out of an extremely strong material, made by a friend of mine who has a workshop, it is stainless steel, but one of the toughest grades I am told, so basically it is a custom made top hat key that is retained by the original spring with a shortened tang as the tang will only engage in a C20 slot but not into the gearbox shaft, that slot is occupied by the key, if this fails then it is Loctite or a new input shaft and C3 shoe carrier as Gregg suggests above, I am trying to avoid that at all costs.


IMG_4961.JPG
IMG_4962.JPG
IMG_4963.JPG
IMG_4964.JPG
IMG_4965.JPG
IMG_4967.JPG
 

SteveW

Well Known and Active Forum User
VOC Member
This may not be related, but my clutch was maddingly getting slack all the time until I found in an obscure forum that the "C19" shim should allow only .010" clearance behind C20. Mine was over .080" and I was always adjusting it. Good luck.
 

Peter Holmes

Well Known and Active Forum User
VOC Member
Steve, Yes .080" is an excessive clearance, but even with that amount of clearance, the C20 nut could only unscrew itself further, (noticeable when the handlebar lever ceases to lift the clutch), if the bent tang on the C45 spring snaps off, is this what was happening to your bike?
 
Top