I have a 2004 sportsman 500, I bought it about a year ago. When I bought it I did not realize it but it was stuck in 4 wheel drive all the time, and would not dis-engage, when we realized this, we changed out the oil in the front differential, tested it, and it was still doing same thing, stuck in 4 wheel drive. We left it like that because we did not mind it too much. When we took the 4 wheeler out for the first time this season we realized that it is now not engaging at all, but the light on the screen shows that it is engaging. So now the 4 wheeler is stuck in 2wd, and I do not know where to begin. I do not know much about 4 wheelers, so any help will be very much appreciated.