I've had this tractor for 3 years, the front end 4WD unit has blown up on me 3 times in the 3 years. Average about 1000 bucks a repair, and that's just for parts. We do live on "non flat" terrain, that's why I needed 4WD.
First failure was the wheel gears on both front wheels, second failure was the ring and pinion gears. Third blow-up; I'll find out in a couple days. Front left wheel won't rotate, so probably in the hub gear assembly.