left wheel lockup

hello, I have a 1996 gh 720k mower, as I was mowing the left wheel locked up and spun me around. just before this happened I heard a noise that sounded like I ran a stick or something over, I had not, the wheel will move a small amount, basically from the 11 to 1 position on a clock, it sounds like it wants to continue but will not. does anyone on here have any ideas what to look for? thanks!

mystery solved, I pulled the final drive apart and found several gears damaged, some had teeth broken off. can anyone give me contact info for the company so I can order parts direct. thank you

http://www.grasshoppermower.com/

I don't believe you can order parts from their website although you can find dealers or maybe get recommendations from them on OEM parts sellers.