I have never owned or worked on one but i have heard about some.
If i understand it correctly there are 2 things that may have broken.
The input shaft and there is a mod to correct and improve that.
I saw a article on this and looked great.
The other is the output shaft to rear end, which is a couple of thing that may have broken or just come apart?
This can be unhooked so tractor can roll free.
Do searches here and other tractor forums on sos problems.
Pull out your manual and look for access panels and associated connections.
In the next day or so i am sure there are others who know more will chime in.
DS