I bought my 2006 Sportsman 500 HO in 2007 and I mostly use it for carrying yard tools, etc. It is a mule to me more or less. It has < 200 hrs and about 200 miles. I have changed oil once and it stays mostly in my garage while not being used. It shifts well and about the only thing I have done to it is replace the battery. However, recently it started slightly jerking. I noticed it in handle bars. It is more profound in 2×4 than AWD but still subtle. In 2×4 I can see drive shaft spinning to move front differtential. At idle there is no jerking. Jerking appears to happen only while moving. I raised front end and didn’t notice any unusual play in ball joints or drive U joints. I have shaken ATV back and forth and side to side and have not noticed any excessive movement. I have not noticed any lubrication drips where I park it in my garage. Any suggestion?