Craftsman DYT 4000 transaxle problem

M/N 917.273620
Hydro Gear 314-0510 Transaxle
Last year it started to lose speed in reverse, got to the point it would barely move. Did notice that if I pulled really hard on the motion control lever it would move a little faster. Forward seemed to be fine.
Now this year it is losing forward, it can barely climb a hill. But on level ground it still seems to have about the same top speed.
I have purged the transmission and checked the linkage for the motion control, everything seems fine.
Does anyone have any recommendations on what to do next?
 
Thank You for your time.