No reverse on right side of a cadet rz50

[meself]

I bought an rz50 off my friend, I have mowed with it for years.
It lost reverse on the right side, but forward is fine. I do not think it is the pump or forward would not work.
The linkage looks to be fine. Any suggestions? Also ,when mowing with it if you pull the right lateral back, you can feel a surging in the lat.