This why we made this prop stronger Andy, used the stronger universals and removed the center bearing out of the picture. No prop twisting.
Side shafts break for different reasons, I only saw this one happening:
Once 4x4 rolled back a bit on an uneven incline, Driver puts foot, wheel bounced and snap the side shaft( was the local diff side shaft on the local diff) on the side the wheel bounced.
Yes gearboxes can break, yet still the G52 is still quite used a lot over seas for these crazy trail 4x4's in America. Its strong, easy to maintain and parts are cheap. Only downfall is the 5th, but like on lots of vehicles, don't tow in 5th.
Then diff's. Yes again they break. How ever the Import diff much stronger than the Local diff. If you really want to break them just jump the 4x4 in the air. Keep the throttle flat and see you diff gooooo. Or more plainly, drive with a warm diff through water and see what happens lol, over the past 15 years I saw more diff failures because of water damage than ones breaking.
Then if you want to convert, spend time doing the conversion, speak to guys that done it, hear what they have to say how they made it better. Then plan ahead. Also try if you can to do it yourself, you get to understand it better. Carefull with some that says he done it very cheap.
DONT try to save money and get it done the cheapest way, this is where you loose on the long end.