My 69 Bonneville jumps out of 3rd gear. Typically it happens when first opening the throttle then easing of and then opening the throttle again. If I after this put it back in gear it usually stays there. It also helps being "firm" with the foot when first putting it in 3rd gear.

I suppose this is due to wear? Is the only remedy to buy new parts or is there anything else I can do? The new parts being kinda expensive. Do you usually need to buy for both main and layshaft?
I guess It will be easier to tell once the gearbox is apart and I can post some pictures of it but any info on what I have ahead of me would be much appreciated.


I make misstakes on a daily basis!
Behold a selection of my different means of transportation (very poorly updated these days...)