Update on tires don't spin. I have done some more testing and changed hydro filter. It will spin in low gear if you jerk it around and drive like an idiot. Overall I think it is performing as it is supposed to. Traction is just not a problem. I kind of miss the old gear drive...This video link is the rest of the story.
Do you keep your axles locked? I wouldn't. R1 tires, loaded, that won't spin? I wouldn't expect them to,
But my experience from what I know (not much)...... A hydrostatic trans is not an Automatic. Maybe closer to a CVT. It doesn't have gears, it uses a pump(s) depending on how far you depress the pedal. From what I've read, it generates more pumping power the more you depress the pedal.
I know this, in an automobile or truck, an automatic is superior to a shick stiff in every way. Power (especially torque), economy.... Virtually every mechanical advantage is superior in the new auto transmissions. The newer Mustang GT with the auto is an 11 second car right out of the box. That's moving. The 6 speed stick can't touch it.
Truth is, however, a hydro is kind of a dinosaur. But don't under-estimate the power they can put on the ground. Just because the application is smoother doesn't mean you're losing a whole lot. You do lose some because, like I said, the hydro is like 1930's tech but still, they're good transmissions