Fitting dynamo G80S

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
SPRIDDLER
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Re: Fitting dynamo G80S

Post by SPRIDDLER »

markwhitelock wrote:
The splines are really worn, I imagine the Cush drive movement will take up slack but does this look dangerous/excessive?
Yes, pretty well worn (knackered in fact). I thought that from seeing your earlier photos. If it was mine I'd still use it and see how it behaves as replacing it is quite a big job; splitting the c/case, crankpin (big end) and flywheels, (then it might be necessary/prudent to replace the main bearings, timing side bush...…….. :roll: ) Are the splines inside the cam o.k?
The parts are laid out as I took them off,
I hope they weren't, but if that is the case it was wrong. The small cam should be between the spring and the sprocket, mating with the other half of the cam on the sprocket.
there was no spacer to remove. Is the spacer loose or is it in there somewhere and I'm not seeing it?!
As Pharisee said, the spacer would appear to be there. It bears against the inner race of the outer main bearing. You'll need to fish it out to check it's the right width.
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SPRIDDLER
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Re: Fitting dynamo G80S

Post by SPRIDDLER »

Having said that I would try the drive side axle as it is I did replace mine on a new-to-me 350 as there was other damage and I was preparing for a 2,400 mile solo European camping tour.
The pic doesn't show the axle wear very well but if you zoom on it you'll see that it was almost as bad as yours.
Axle wear (640x495).jpg
Axle wear snip.jpg
EDIT;
Looking at your pic again it may be showing the shoulder on the axle and not a spacer. Compare it with my pic of my damaged axle although if it is the axle shoulder rather than a spacer we should be seeing the main bearing inner race. :?
Axle shoulder.jpg
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ajscomboman
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Re: Fitting dynamo G80S

Post by ajscomboman »

I see no spacer fitted, but I know a man that has one on his shelf! Am I going to have to bail you out the s**t again? :D
markwhitelock
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Re: Fitting dynamo G80S

Post by markwhitelock »

Hahaha, yes please Rob! :beer:

I've tried getting mole grips on but nothing is moving, I'm pretty sure it is the shoulder rather than a spacer.

Image
Image

Incidentally, what should the distance from the end of the splines to the shoulder be? I'm seeing 20mm, if a spacer was there what would it be?
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Re: Fitting dynamo G80S

Post by SPRIDDLER »

markwhitelock wrote:
Incidentally, what should the distance from the end of the splines to the shoulder be? I'm seeing 20mm, if a spacer was there what would it be?
20mm looks about right, so it's the shoulder we can see and not the spacer.

Here are a couple of pics of a '54 axle which will be the same as yours
CIMG1842.JPG
CIMG1848.JPG
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Re: Fitting dynamo G80S

Post by markwhitelock »

That's really helpful, thanks Spriddler
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clive
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Re: Fitting dynamo G80S

Post by clive »

Right at the beginning of this thread i said it appeared no spacer was fitted. Obvious from the closeness of the dynamo sprocket to the crankcase! :headbang:
As to the wear on the splines it looks to be about 1/3 worn and there will be similar wear on the small cam. Whether to replace it depends on the depth of your pockets and the use you are intending for the bike. If you replace it you will probably decide that you should replace the big end and main bearings whilst you have it apart . Then there may well be wear in the timing side bush and oh look it could do with a rebore and new piston.
Expensive if you are only going to do the odd local run and trailer it to rallies. Possibly worth doing if you are going to join us travelling to the International rallies (when we are allowed) or other long distance events.

I continued to use a shaft similar to yours on a G80 with double adult sidecar. The splines did eventually give up and all that happened was i lost drive as the whole lot spun on the shaft.
clive
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