Could be a stripped out hub and axle splines i have seen that before. Check the nut that holds the hub on the axle, make sure the hub is fully seated onto the axle and the nut all the way tight. Its also possible the differential is shot in the rear end, would have to drain the oil and see what it looks like. If you drain the oil then put rear end up on a jackstand and spin the wheels you can listen for noises and see if the diff is working.
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1984 Honda ATC200ES "Big Red"
1982 ATC200E "Hondie"
1988 TRX300FW "Project Quad" Still in progress....