Can't engage first gear

[pallijen]

Matchless G3LS 1953, Burman B52 'box.
Hi all, as some of you may be aware I had some clutch and gear change problems. I have since fitted the correct clutch, stripped out the gearbox and put back together (no oil leaks now, was no seal fitted on the gearchange lever) with new gaskets. My problem now is that 1st gear will not engage even when engine is not running. Put it into first gear and turned back wheel but nothing else turns. There seems to be normal resistance when turning the back wheel by hand but everything to do with what's in the primary chaincase doesn't move. As I turn the back wheel al that is heard is a click every couple of seconds. Is it possible one of the gears (first) could be the wrong way round? I had a bitsa clutch (4 spring, shallower centre, one plate short) and got all the correct parts which mean't that I needed an extra spring. Would a new spring make that much difference to the old ones? I am thinking (as advised previously) of renewing all the springs but don't think this will make a difference to the first gear problem. Do clutch cables stretch much? My clutch pushrod is 9.75" long (not 9 7/8"). I have to use almost all adjustment at gearbox side and lever side. Even though there is play at the lever side when adjusting from the 'box side it seems to pull on the clutch activating arm in the 'box, does the spring on the clutch activating arm (the one with the 3 balls type). Making good progress, getting dizzy just riding round the block. Thanks to all for previous advice. Paul J

[SPRIDDLER]

Matchless G3LS 1953, Burman B52 'box.
My problem now is that 1st gear will not engage even when engine is not running. ......I needed an extra [clutch pressure plate] spring. Would a new spring [that I have fitted] make that much difference to the old ones?

No. It certainly won't be the reason why you can't engage 1st gear. Does the clutch free and not turn th'engine when you pull the bar lever in and operate the kickstart when in Neutral? Presumably it does and you have been pulling away in 2nd..........and when stopping selecting Neutral?

Making good progress, getting dizzy just riding round the block.

I can't see that it's a clutch cable stretch (they don't stretch) or a clutch adjustment issue as (presumably) when riding it around the block the other gears are engaging o.k.
It does sound like a g/box internal assembly error, but I can't see anything from here.

[pallijen]

Hi Spriddler, the gearbox works fine in all gears except 1st. I've just ordered some new springs anyway, I know the new one that was fitted alongside the 4 old ones is considerably stronger by the difference in tension I have to apply. Yes the clutch releases when I kick the bike over, no clutch slip when riding, back to work for a few days then I'll fit the new springs, don't think that is the problem though. Thanks, Paul J

[clive]

best to only raise the same problem in one thread. I have answered on the other one.

[oldandsmelly]

It is possible to fit the first sliding gear (on the layshaft) the wrong way round. I'm not sure if the inner casing would go back on like that, but looking at my spare piles of gears and shafts, I think it might. First gear obviously wouldn't select at all like that.

The holes on the first layshaft gear (which is the one next to the inner case on the layshaft) need to face inwards to mate with the sliding dog gear. If you haven't got a copy of the exploded B52 diagram, it might help you greatly. This diagram is elsewhere on this forum, if you can't find it I'll stick it here.

Another possibility for not getting first gear is the selection mechanism. From second thru neutral to first seems to be the move that suffers most when the selection mechanism is worn or faulty. Take off the outer gearbox cover and check things like the spring in the case that pushes the selection plate back against the selector drum, the drum itself and the little bullet shaped thing that sits under under selector drum. The spring under the bullet thing can fail thru rust and old age and the bullet itself can wear to flat and roundish rather than the true pointy profile.