Reassembling a '78 R80 5-speed tranny, won't shift right...

[qford]

I'm reassembling a '78 R80 5-speed after a failed-bearing problem, but when I install the shifting mechanism, it won't shift through the whole pattern, hanging up after clicking from 1st through neutral and (sometimes) into 2nd (sometimes stopping before the spring-loaded roller cam drops completely into the round groove for 2nd), sometimes locking up there completely (no movement up OR down).

Any thoughts, or information you could point me to?

Secondarily - maybe a problem, maybe not - the top (largest) gear on the one shaft has about 1/4" of up-and-down play in it that keeps the other shaft gears from hand rotating when gravity lets the large gear drop down to its resting height when the trans is on the workbench. Raising it up by hand that 1/4" allows both shafts to rotate.

Any idea what's up with that? Maybe the gear "dropping down" won't happen when the trans is horizontal in the bike, but the idea of it sliding over that little bit and locking the gears up at speed bothers me quite a bit.

I DID NOT disassemble the gear shafts when I replaced the bearing, so everything should be as it came out, and I'm mystified as to why there should be that play in the large gear - as if there should be some spacer to hold it in its correct position.

Any thoughts or help would be MUCH appreciated!

[Airbear]

Gford, I replied to your queries in the Woodworker's Guide thread.
I hope there is a happy outcome.

[disston]

Don't know about that second problem you have with the 5th gear. Is it a problem? I haven't had one apart recently. I'll try to look at some parts later if I get to the shop.

But as far as shifting the transmission on the bench? They don't shift on the bench very well if at all. So you can't infer much from this. Having a spare clutch disc in the input shaft to turn by hand will help. I usually have to jiggle things inside to make them shift.

[PAS]

qford, I have that shaft in my hand with the flange end pointed up. I have the 1/4" gap below the large gear, the next gear down can be raised up to allow the other gears to turn. Not sure if that is what your talking about.