We have an old loader with Dana 60 diff., spider gears stripped twice in 30 years service. not bad I would say. We currently have a Willmar and really like it. I am sure we will invest far more money in the hydraulic system than the old one in 30 years. At least with the swinger you only have one hyd. motor. As with any new machine, dealer and service can be the deal maker.
We were lucky in that a local repair shop happened to have a whole rear end out of the same loader and we just swapped it out. I would think a good drive-line shop should be able to help you out. I will check and see if I can get some part numbers from the local guy. The last time the gears stripped, if busted the whole inner gear carrier. Another thought. Some one should be able to cut down and make narrower a truck rear end.
What are you going to use it for?
If you're looking new, I would suggest Gehl, which was built in conjunction with/ Wacker Neuson although it's made in South Dokota. I have the AL540, and my climber has the AL140. I have oodles of video of them.