Marooka MST-700 slow moving

Looking for some info on a marooka MST-700...she moves forward ok, wont turn to the right, and barely turns to the left and it's all she got to move backwards, I found a new drive hose had been put on and the system filled with ATF, which I know is bad since the system calls for aw46..and I understand it's a closed looped system but I'm not sure How to go about checking what's bad, a relief in the drive motors? Charge pressure not holding? Dealer not being friendly at...

Marooka MST-700 slow moving

Marooka MST-700 slow moving