How to take the rear wheel?

i found out the rear wheel on my 70's craftsman tractor on the right has a chain and goes to the gear box and i was thinking to take out the left wheel to see if it could slide out and it did to see if the other wheel had problems so thats what i did so iwant to know if maybe this whole problem maybe it was attached to gear box or etc what should i do now if thats the problem.