Was the tire repair a rear tire? If so, it is likey the keyslipped out and the axel is turning inside your wheel. Easy check- remove the little hubcap, start your tractor, put it in gear and watch- or have some one watch if the axel is turning inside the wheel. Easy fix is to remove the clip again and insert a new key when the grooves are lined up. If you have input to the transaxel and both wheel keys are still in place- your issue is internal and relativelyt costly. Good luck.
to, May 2006