On the plus side, you did rip the heart out of one of those evil four wheeled contraptions and gave it a descent home. The shaft drive is what makes it utility, without that, you've got a electric start, reverse equipped, overly heavy 200X for the lush crowd, who may break a nail on the e-start button. Now, I've got to pick on you some, although you should understand I wouldn't try to stop someone from building whatever they like, but I can still poke fun. The differential shows no sign of going out anytime soon. I've done a lot of riding on it in those years.
I've even done hundred+ mile trail days on it, crossed countless rivers and streams, been in snow and rain, ran over many a rock and stick that can get caught in a chain.
I've been riding a 200ES for 8-10 years and not so much as a squeak from the differential in that time.
No, I've never had to replace a differential on my ATC, because I maintain it, but I've seen several other people complain about the repair costs after they neglected it for years.