gear indexing

I have just rebuilt my 71 750 roadster gear box. The layshaft bearing was wrecked and the kickstart shaft was cracked. I replaced all the ball bearings, sleeve gear bushes, the kickstart shaft, pawl, spring, and bush, and the kick start spring. The shafts, gears, forks, and cam looked fine and measured good.

I indexed the cam carefully. Put together dry, it shifted through the gears.

Now, all put together, it goes easily and silently into first, neutral, and then will not go into second.

On the road, it can be coaxed into second or third with careful shifting without the clutch and at fairly high engine speed.

Down shifting doesn't really work well either.

Does anyone have any idea what I have done wrong? What should the next step be?

Many thanks!

Mike Provence

As even a "spanner" man like me can pull a norton gearbox apart & make it work. My guess is you only need to pull the covers off & see what you have not put back quite right.

No doubt you would have a manual that tells you what to do. If you check again & still can't work it out, one of the more technical blokes will surely have ideas to throw at you.

Maybe just pull the cases off & do it over to make sure you haven't missed something. Maybe that cam adjustment is a tooth out ?

Thanks for the reply. The quadrant may be slightly in the wrong position. Would that cause these symptoms? Can I advance it a tooth or two without dismantling the entire box?
MP

On my gearbox rebuild I initially installed the quadrant one tooth off.

It seemed to shift fine until I installed the inner cover and I couldn't shift into first. It also created all sorts of strange shifting behavior.

The quadrant arm was hitting the bottom of the of the inner cover slot. The instruction to have the quadrant arm "line up" with the case stud was a bit of a red herring - on my box the arm locates either a little above or below depending on the tooth- my first guess was slightly below the stud~ bad guess.

Alas, there was nothing to do but pull it all apart.

Good luck.

Phil