OK I'm no expert by any measure but since no one else has chimed in I'll put my 2cents in.
(and most likely look foolish )

can you verify that the belt/pulley is turning the trans input shaft ?

I'm hoping you got lucky and maybe sheared the key there or at one of the wheel hubs.

 

Well, Any help I can get even from non-experts:lmao: I'll check all of that Thanks

 

The only reason I thought of that is because I got a tractor and after I got it to run it wouldnt move then after looking around for a while I notice the shaft rotating in the wheel hub and thought DUH they just shoved some tires on with no key.

I really hope its something that simple for you.
If its not the pulley on the input shaft or one of the hubs I'd guess in the trans at that point.

 

Team Cheap , you are the MAN!! The key was missing out of the rear axle. You saved me Hundreds! If only I know where to send it, Oh well, Thanks

 

Oh cool, I love it when its simple and cheap.