[C-Leigh Racing]

If your talking about the pin in the ratchet arm part of the shift drum, down under the clutch basket, where the shift lever arm fits of the little round L shaped bushing ?.
If that pin is coming out, which would be a first I've ever heard of,, you could spot weld it I guess on the back side once pressed back into place or either replace that little arm.
If that is what it is, first time I've ever heard of that pin being loose enough to come out. Odd things can happen though.
Neil