SEALED BEARING for Main Gearbox Output shaft

[Les Howard]

I fitted a 2x sealed (2RS) type bearing in my gearbox, but before completing the rebuild I'm thinking maybe I should remove the INNER seal?..I can't help think the bearing might last better if lubricated from the gearbox oil or maybe the totally "sealed for life" bearing will have a cleaner longer life?...Much appreciate any hands on views on this topic please....Thanks

[Pharisee]

I've just bought a new output sleeve bearing for the AMC box fitted to my Norton. Andover Norton offer either an open bearing or one with a single seal. I would still fit the external oil seal as well, though... to be sure, to be sure!!

[Joker_Bones]

IMG_20221030_110709.jpg

I have recently built up a couple of AMC gearboxes.
I bought sealed bearings and pinged out the inner seals. I wasn't sure it was necessary, the bearings were not sealed as such, more shielded with a metal disk, I imagine oil would have got in there anyway... But I decided to remove the inner shields.

While working on the gearboxes I referred to the animated diagram of the AMC box and noticed it was created by Les Howard... Are you the same Les Howard?

[Les Howard]

Thanks for your feedback Pharisee and Mr Bones. Yes I think I'll remove the inner rubber seal. It is a quality SKF bearing and I would imagine that it would have a good service life but not being able to see how much grease is inside is too much of a worry for me. The box, by the way, is an Albion fitted to a Royal Enfield Constellation and not the AMC box. It operates in a very different manner, selector wise * The AMC box above is nicely clean and some owners use a roller bearing nowadays for the layshaft bearing. Thanks for taking a look at the AMC diagrams I made up some years back. Unfortunately with older "Word" software it used to create a sort of gearchange effect if you keyed up or down but it does not seem to do that now. It gave a better idea of how the gears were swapped around...Thanks again, hopefully I'll be able to pick out the inner seal tomorrow and be in good company....
* This can be viewed on the Hitchcock's tech info on the diagram I did for that box....

[Joker_Bones]

I didn't notice the lack of animation, it's still an excellent explanation without it...
It's certainly done the rounds, I've seen it referred to on many forums and have found it in different places whenever I have looked for it.
I'd not seen the diagram for the albion box, I've never worked on one, curiosity led to visit to the hitchcocks site

[Les Howard]

Thanks very much for the feedback on the diagrams Mr Bones, it makes the effort worthwhile. Hope the rest of the gearbox rebuild goes well. I can see you are making an excellent job of it so far. Getting it immaculately clean is always the best way to proceed. Fitting bearings inside cases can be difficult but made easier if you make up a mandrill even in wood to lower the bearing absolutely square. With the cases very hot, even as high as 200 deg, they fall into position. With just 100 deg, they can often touch slightly, then heat up and jam needing one to bash them in...Looks like you've done it nicely...Well done ...Will remove the inner rubber seal on my main bearing today....

[Joker_Bones]

Yes... I've been there, got the bearing started cockeyed and then it jams as the case cools. Now, whenever possible I like to fit them with a puller with some spacers to keep everything square, that's other bits and pieces in the above photo.
Both gearboxes are built up. One is fitted to a 350 and the other is ready to replace a B52 box on another bike.
The only issue I had was, on one of them, after assembly there was a nasty clacking noise when rotated by hand in 4th gear. I looked at your diagram to see which parts engaged with which while attempting find the cause of the clacking noise. It turned out the scallop in one of the selector forks didn't provide enough clearance and the fork was just contacting one of the gears. In 1st, 2nd & 3rd the fork was in a diffent position and clear of the gear it was contacting

IMG_20221104_145524.jpg

[Les Howard]

Well I managed it but not easy in-situ . I spent at least half an hour trying as there is so little width inside the Albion box and hard to get the full leverage required. Anyway. The bearing WAS full of a white/clear grease and I guess knowing that maybe I would have left it. Then again the original bike had open bearings....Oh well, I reckon my total mileage on the bike is unlikely to exceed 2K miles before I snuff it. I guess the real pleasure for me is the restoration, but someone one day will have a mostly trouble free bike as far as I can make it...

[Les Howard]

Ahh just seen your latest post...The noise problem....yes this has reminded me that the pins on the selector arms can touch on the cam ratchet so are ground off a little on one them...I won't say too much and I will have to think more on it as the last AMC box I restored was some years back and I have forgotten what the fault was...will try to remember....

[Les Howard]

MR BONES: Had a good think back and the problem was with a Norton "Laydown" gearbox (forerunner to the AMC box)...it was with the selector pins being ground off on one of them so they would not touch the rotating cam plate so nothing like your problem with the rotating gears. Hopefully you can get to the reason why that selector fork touches. I have a feeling perhaps they can be accidently transposed as they look very similar...just a thought as it's several years since I last rebuilt an AMC box...