Lightweight gearbox problem

[Ozmadman]

That's got to be wrong. The bushes should be at each end of the sleeve gear...

I agree, here is a picture of mine showing the position of the outer bush, there should be a gap between the bushes as far as I remember. BTW this is how a 20 tooth sprocket will look

[Steve S]

Thanks Guys, this explains why the clutch body appeared to be "loose" ie wobbling a bit when I came to undo the nut.

Steve S.

[clanger9]

Also a good idea to check for wear on the clutch centre splines. Just check the clutch fits securely onto the splines.
"Wobbly clutch" is a symptom of wear hear and is a common fault...

Here's a picture of the (extreme) wear I found on my bike: http://www.jampot.com/forum/viewtopic.p ... 20#p142193

[Ozmadman]

And I would loctite that nut on when it comes time for re-assembly

[Steve S]

Ha!

Now I have my replacement gears and also know how to post pictures, so here goes, over 4 posts I'm afraid.

Pics 1 & 2 new and old 3rd gears, new one from Les at Russel Motors thanks.

Pic 3, new and old mainshaft sleeve gears. new one obtained form Norvil - great service, thanks Roland, Les et al.

Steve S

[Steve S]

More gear pictures...

Spring for cam plate selector pawl? Looks worn to me, length is 1 3/8 or 35 mm

Mystery brass ring found between oil seal and sprocket, do I need this?

Nice sleeve gear bearing shoulder

Steve S.

[Steve S]

More pics...


Main output bearing, this looks fine to me, is there a definitive way of determining if it should be replaced?

Selector forks, look good to me

Cam plate wear, just a faint line, should be ok?

Steve S.

[Steve S]

Last post of pictures...

Clutch centre - looks ok but was wobbly when I took it off, mind you the nut wasn't tight

Other bushes in housing- should they be replaced?

Steve S.

[Ozmadman]

Ha!

Now I have my replacement gears and also know how to post pictures, so here goes, over 4 posts I'm afraid.

Pics 1 & 2 new and old 3rd gears, new one from Les at Russel Motors thanks.

Pic 3, new and old mainshaft sleeve gears. new one obtained form Norvil - great service, thanks Roland, Les et al.

Steve S

Are all the replacement gears including the sleeve gear new? if so you did well to get them. Even your original sleeve gear looks fine and if that was the one that came out of the box I suspect the large bearing will be fine as well. Just clean it out with some white spirit or similar, dry it and re oil it. If it runs smoothly then it will be fine(that bearing is over £70 new!!) Who's Norvill and where did you get the sleeve gear from?(how much?) and does it come with the bushes in it as I could do with a good one as mine is just passable? I would replace the bronze layshaft bush (the one next to that main bearing as that looks a bit worn and they can wear oval ( see my earlier post on this bush ) and that detent plunger (think it should have a better point on it) and spring. You will need to knock out that tin end cap to replace the bush then tap it back with some sealer when you are done, be careful with it as they are not available as far as I know and not interchangeable as both are slightly different sizes. The other bushes in your picture dont really wear much. The line in the gear change cam plate should be ok as long is it is just surface not too deep. The clutch can be a bit wobbly anyway but as long as the centre and mainshaft splines are a good fit together you should be ok. And, you don't need that brass shim thing, all that should be there is a sleeve for the seal to run on, this pushes over the sleeve gear splines. Hard to tell looking at the selector forks but these are rugged basic boxes and they will probably be ok if you cant get your hands on replacements.. Looks great though the newest lightweight box in town!! let us know how you get on

[Steve S]

Thanks Paul for your detailed advice, I can see some light now at the end of the very long tunnel!

Sleeve gear, complete with bushes, came from Norvil Motorcycle Company 01543 278008, very helpful, I sent mine to Les Embrey, their parts specialist who said he would be able to sort me out. Came back very quickly, said to be used but I cannot see a single mark on it, £75 + VAT and postage. They are worth a try for other parts as well I'm sure as Les said he had unopened boxes of spares!

The third gear is new and came from Russel Engineering for £40 inc. Now looking at my original one it only differs in the width of the dogs. The pegs are the same size and I guess mine would have been OK but at the time I thought I had the wrong, earlier gear which engages in the early sleeve gear which had holes rather than dogs.

My layshaft bush is rotating in the housing - will I be able to pull it out without removing the end cap etc?

Does the output shaft oil seal just prise out from the outside?

The detent plunger has a reasonable point on it which doesn't show in the photo.

Once I get the box back together I'll review the clutch centre wobble and maybe order a 20 tooth sprocket, rear sprocket and chain making the transmission good to go.

Need to check the swinging arm bearings and rear shocks as well.

Photo attached is of the bike before I started messing with it.

Steve S.