Boy, I'm probably comparing Apple's to oranges here. I got an old allis Chalmers 185 and it got hung up in reverse. I had to pull the top off the transmission and realign every thing and get the shifting forks back in the right spot. Not really expensive, just a big inconvenience and hassle. Now it works ok. I kind of baby it and be gentle when shifting. Don't know what caused it or why it did it. It has only happneed once. Might have something to do with the fact I have 14,000+ hours on the tractor. I don't know how exactly a Kubota works. This is just an idea of where you might start.