It was run for a long time with nothing but mud for lubrication. Apparently the seals went bad and were not replaced. I understand that in Japan, these tractors often sit in flooded rice paddies for months. I can get all of the required parts new to repair it except for the tower gears. The needle bearings were in little bits, and the inside of the tower gears, as well as the vertical pivot shaft on which the tower gears run were chewed up pretty badly. I attached a photo - as you can see, the rest of the gears aren't in great shape either.
The tractor was a free-bee, but I've already rebuilt the engine, with the promise of parts available for the axle, only to find later that the dealer could find only one of the two tower gears shown to be available. I would hate to leave the tractor like it is. I suppose an alternative would be to grind the shafts and the gears, and try to put sleeves in there along with new needle bearings. Or just make it 2wd....
Greg