Help With '39 Transmission?

. . .

 

I would pull off the top plate and look to see if the forks might be bent
or someting wrong with them.

 

Forward and reverse would be difficult to do as they use the same slider gear. It could be that there is play in the shifter fork for the 2nd/3rd syncro allowing the syncro to slide while you have it in first and that will lock up the trans. You will need to pull the shifter housing off the top and see what is up -- loose parts in the shifter etc.

 

There was a very comprehensive book recently published on rebuilding these gearboxes, I think it was $39 and probably well worth purchasing if you plan on working on your gearbox. There is also a good diagram in the Bishop/Tardell AV8 book...