1962 A10 Gearbox

[cyclegeezer]

I'm new here and am having a problem with my 1962 A10 gearbox.  It jumps out of 3rd gear nearly every time. No problem with any of the other gears.  I just replaced all the bushings, bearings and sleeves hoping that would help but no dice.  Looking through the inspection window on the box I notice some slop in the selector forks when in 3rd.  The gear pair have noticeable wear on the face of the teeth, the dogs don't appear to be rounded.  I haven't tried replacing the gear pair under the assumption that any other pair of used gears will also be worn about the same.  Has anyone else had this problem and repaired it?  Thanks for any help.

Keith

[Goldy]

Hi cyclegezzer welcome. I had the same problem when I rebuilt my box. By experimenting I found that if I just touched the gear lever with my foot after each gear change it did not happen and so this narrowed it down to the gear selection. The problem was that the new splindle bush that I had fitted was just a few thou too thick on the bush shoulder. This was making the selector spindle bind slightly. I also decided there was slight wear on the selector plate and I renwed this. One thing that I did when rebuilding was to fit the mainshaft with gears into the box but nothing else. I then fitted the cover and checked for correct fit and end float. I then removed the mainshaft and fitted the layshaft and did the same again. This just makes sure that before fitting the selector and everything else you know that both shafts fit correctly. all the best Goldy

[muskrat]

G'day cyclegeezer, welcome to the forum.
                                                         Also try tightening up the detent spring a turn or two. If it persists I'd look at the camplate for wear in the grooves or selector forks. Sounds like it's not engaging fully.
Cheers

[cyclegeezer]

Thanks to you both, excellent advice which I will put in practice.  I'll let you know the results.