Not familar with that wheel setup but they usually have locking square key that locks the rim on the rear end axle. If this model has the C clip that holes the wheel on I would check the key. maybe you didn't notice it when you pulled the wheel assy off? If you bolt the wheel on it won't have the square locking key about 1 1/2 long or so.

rcmoser,I thank you very much. This was my first experience removing and replacing a wheel on the tractor and I did not notice the locking square key. After reading your post, I found the key on the floor. I inserted the key and my problem was solved. Again, thank you very much.

Since the wheel was easy to remove now, might i suggest removing it again, and coating the axle with grease, then replacing the wheel, and the key, so next time you have to remove it, it won't be rusted on! Which presents a whole new set of circumstances! And, do the other side too!