New riding mower xt2 cadet

I have a 2006 cub GT3200 . I bought it new to help with the landscaping when we built our house. The things a small dozer, you chain it up and it will move some dirt .
I've had to replace to rear ends . 1 my fault pushing it to hard and the second Cub Cadet failing to instruct how to use differential lock. It doesn't work like a big tractor and if not used correctly will shear teeth in the diff. Nothing about the differential lock in the manual or on line . Both fixes about $3000. a piece . The bagging system sucks has never worked well clogs up, but all in all it has exceeded what it was built for. Its too bad Cub sold out to MTD.

I`m wondering how old you guys mowers are, john deere bought out most all the lawnmower brands around here yrs ago , never see murrays, mtd`s hardly ever, and all the offshoots that were cheaper.. They bought out about 6-7 diff. brands > ???