Transmission Leaking

I have a MK III with a transmission leak. I have narrowed it downto the shaft for the gradiant on the front of the trans. I managed to put a new o-ring on the shaft but it is still leaking. I get enough oil from the shaft that is drips down the folded up center stand and drip on the floor after a longer ride. Now the question

How far down do I need to strip the transmission to get the gradiant out?
I have never taken down a Norton transmission, but I have taken a car completely apart and put it back together. Will this be a difficult job?
Is there a brass bushing that could have gone bad?
Any thoughts on how to keep the oil inside the transmission?

O-ring should really take care of it. Yes there is a brass bushing under the o-ring, but that is unlikely to cause the leak, there is no reason for that bushing to fail, except extremely high mileage. Try another o-ring, and maybe use some sauce. Removing the gradient and bushing means removing all the gears as I remember and involves removing the GB, it comes out from the inside. I stand to be corrected as usual. Also check for another leak, it may not be what you think.

Dave
69S

Thanks for the input. I was afraid of a total box tear down. I didn't put any "sauce" when I changed the o-ring last time. Are you taking about grease?