Looked like to me the ta clutch was not releasing. To much free play?? Did you check the adjustment before disassembly. Was the large nut for the ta pressure plate tight with the lock ring, have seen those loosen up?
Is the rear axle seal just an easy pop it out and replace it. Axle is tight with no movement with a dial indicator. Just want to be sure or should the axle housing be removed. Tractor makes no different sounds and no shavings in the oil.