Posted on a similar thread but thought I'd start my own and add a few pics. The tractor is a 2008 and belongs to a friend who's a landscaper. Just rolled over 600 hours when the differential came apart and lost rear drive. All ten bolts worked loose, broke off or fell out of the bull gear. When that happens the wheels are completely loose and freewheel. The tractor has only a pinion brake so you have no brakes at all. Luckily he was using front wheel assist along with the tiller and loader or it could have been much worse. He was landscaping a yard at a new house on the edge of a long steep hill.
He bought the tractor in 2016 with 180 hours on it. I serviced the transmission and found some aluminum filings so cleaned it up and changed the oil. After 8-10 hours I drained the oil again, checked the screen and found no filings. Don't know if he had any service done since then, I haven't had it in my shop. He said he had been noticing some noise when he'd road the tractor between jobs, but seemed fine when in the dirt or under load. I found all ten bolts in the bottom of the case, all of them are bent and have the threads chewed up. One bolt was broken off in the gear but I was able to screw the piece out with my fingers, no locktite at all on any of the bolts. The case has some minor damage and the differential carrier has the holes egged out. The side cover is destroyed. The bull gear has some marks on the top edge of the teeth but it will clean up with a file. Have most of the cleanup done just waiting on all the parts to come in.