LGT 2654 transmission swap

I was given a LGT 2654 tractor with low hours but it has a Tuff Torq hydraulic transmission and was told that it won't pull good any more and was told he kept putting heavier oil in it and has gear oil in it at this point. From what I have read it seem these transmissions aren't that great to begin with. With that being said is there a transmission that will bolt up and work in place of the Tuff Torq maybe a HydroGear???