I assume that you are noting the differential action? Exactly what issues are you having? No neutral?

When you shift thru the gears and spin the pulley the wheels spin as they should when it's in gear and when you shift it to neutral the wheels stop spinning if you spin the pulley but if you try and roll the tractor while it's in neutral it won't roll one wheel spins forward and one backwards

You state the transaxle was "taken apart" previously, and that gives insight into what is happening now.
Everything about the actions you observe when the wheels rotate opposite directions when wheels are off the ground, and the fact that the tractor will not roll when the wheels are on the ground........................only point up that the DIFFERENTIAL section of the transaxle is functioning exactly as a differential is supposed to. Those actions are not symptomatic of a defect.

The real issue is going to be located somewhere "up stream" in the transmission section of the transaxle.
Based on what you state here, my best guess is that "NEUTRAL position" is actually locking 2 gears together instead of disengaging all contact with the shift key.
If you were not the person who took it apart the first time, you may be missing that maybe one gear was put in place "backward" and the offset in that gear causes the shift key to still be in contact when it should actually be in clearance with that gear.
If you go back into the trans you need to home in on the shifter key and how its notches actually "line up" with the gears that the shifter key passes through.

To further your knowledge of differential behavior, When you have the wheels off the ground and turn the trans input pulley by hand with the trans in some gear.........hold one of the wheels so it can't turn and watch the opposite side wheel rotate at TWICE the RPM compared to when they both turn together.