2005 Polaris Ranger 4x4
 

I'm afraid I know the answer to this but I thought I'd give the forum a try.
I have a 05 Ranger 4x4 with 175 hours on it. Today my 40 year old son borrowed it for a day to work on the farm. He had ridden with me several times and I gave him instructions on operation but this was his first time driving it. When he returned it, it now has a very loud clanking noise and a shudder when you first start to move in H or R. Doesn't seem to do it in L. Doesn't matter where the locking diff or 4 FWD switch is. Once you get rolling the noise and shudder quits.
I haven't done anything to trouble shoot it yet except to jack up the front and turn the wheels. That doesn't seem to make the noise. I suspect the noise is coming from under the seat. Transmission?? How to I go about troubleshooting the problem? I was thinking about putting it up on jack stands and running it while I try to pinpoint the noise. From what I have read, I suspect he might have changed gears while in motion or ran it all day in H at low speed. Probably a gear missing a tooth or two or a chain. I'm not familiar with the internals of the transmission.
Any help or ideas would be appreciated.

2005 Polaris Ranger 4x4
 

Check belt! probably glazed and stretched,if used in hi under load,will cause shudder. Usually does this upon taking off and gets better as clutch gets better bite on belt. I have a chart at work showing 9 different ways to destroy/damage belts,from glazing to separating all the way up to shredding! Have seen just about all 9. Hope that this is just your problem!

2005 Polaris Ranger 4x4
 

Thanks Old Polaris Tech. You were correct. Took the housing off and the belt is missing 5 teeth. I suspect my son was pulling a load in H. The rest of the belt looked like brand new. Picked up a new belt at the local Polaris Dealer and he agreed the belt looked good except for the missing teeth. He also said that most people don't use Low enough and that the belt gets real hot if kept in High for too long while pulling a load. He said at one time Polaris had a lifetime warranty on the belt but had to replace too many so that program has ended.
Thanks again for your help. I hope I can return the favor sometime.