Grasshopper 618 Gemini 771 tranny

[redgrass]

I have a 2002 Grasshopper 618 with the Geminin 771 Hydrostat and approx. 1000 hours or home use * garage kept and well maintaned ). The left tranny is slower than the right enough to make it run in circles if allowed to . Recent fluid change didnt help , same issue hot or cold. Tried adjusting linkage and lever no avail. Any common problem with these that may cause this...
Thanks for the help everyone.
Red

[Sammy]

New belts ?
Pulley wear ?
Slop in linkage ?