Transmission Problems - stuck in 1st & reverse..

[Bittersweet]

Have a 1967 Series IIA Military Truck on an island in Maine. Used the beauty in daily activities and feel lucky to have Her. Last summer transmission started to get stuck in 1st and Reverse gears only. All other gears seem to be normal. The transmission always issued more noise in 1st gear, but this is a stuck in gear issue.

Once you shift into 1st or reverse gear - its locked in place. Only by rolling the truck back and forth will it come reluctantly back to neutral. Anyone have similiar issues, with solutions? Is this a jammed Selector Shaft or a Shaft for Fork or a Steel Ball for Selector that has come loose and fallen into a new location?
Any insights would be greatly appreciated!

[StX_Rovers]

Well, first and reverse share the same gear in a 2A transmission so it is something there.

They do not share the same shifter fork. It is probably worth taking out the centre floorboard and pulling the transmission top cover. The nuts are BSF so be forewarned on the wrenches front but typically they are not too hard to remove, so an adjustable wrench should do the trick. Be sure to look at the service manual before removing the top as there are a couple of detent balls that can fall into the transmission. See if there is anything obvious.

If it was just reverse I would suspect a galled reverse gear shaft but since it is first and reverse I would look more closely at the first gear moving assembly on the main shaft as that is the common part between them.

Good luck.

We use low range and 2nd or 3rd even in situations where 1st high range would work to avoid excessive wearing of first gear, just an FYI.