Sounds like you've got some bearings that are worn out. You didn't say it it was 4WD or not, either way, if the bearings are gone to the point that it locks up, you've probably damaged the bearing races as well. You'll need to take it apart, get new bearings, races, and new seal. If the right side is in this shape, you better look into the left as well. It is probably about to go too. If your's is 4WD, the procedure is more complicated, but it is basically the same advice. Good Luck!