I had something similar happen years ago on my '47 1/2 ton (three speed top loader transmission). In this case, one of the pins came out of the shift interlock. Luckily the pin fell to the bottom of the transmission and did not go through the mesh.

A local machine shop repaired the interlock, but I've since replaced it with a NOS.

Good luck.

Bill


1947 3100 Advanced Design

Never, never, never, never give up. - Churchill