Gator has trouble shifting in and out of gear. Need help finding out year.

Hi,
I'm new to the forum and my gator is having trouble shifting in and out of gear. I want to look up how to fix it but I do not know the year. I just got it. The serial number is M0HX0PB011337. Can anyone tell me the year and model number and maybe give me a clue as to why it shifts hard?
Thanks