Just bought a 2002 big bear 400 2x4 and it is clean bike but got it home and when i drive and turn wheels or back up. It sound like a knocking sound in the back. Does it when i turn wheels or slow reverse. Does anyone have any ideas and what to check. I was told it was bearings or something in the gear area. I am clueless on wheelers, but would like to have an idea on problem. Thanks a lot and you can email me at [email protected]. Like to get it fixed soon.