LS MT357 With S-HST Or Just A HST Transmission

[KCTractors]

I went to my local dealer for a engine filter, engine oil, hydraulic filter and hydro filter. He asked me if the tractor had the S-HST or the HST transmission because they had two different filters. One of the filters had a much bigger hole to screw the filter on.
I never thought to ask him what was the difference in the transmissions. The only thing I could find was that the S means "super", but Super what? Can anybody answer this.
I had to call my wife to go to the garage and see which one I had. I have the " S-HST" in my MT3 57.

 

[GS650GL]

The S stands for servo, not super. The S-HST is servo controlled so the pedals are easier to push and operate smoother. Instead of the hydrostatic swash plate being controlled directly by the pedals like the HST, the pedals operate a hydraulic valve which then operates a hydraulic servo cylinder to move the swash plate. Kind of like a hydraulic power assist for the pedals. I think the filter for the S-HST is orange and has a machined aluminum base with a larger hole.

 

[KCTractors]

The S stands for servo, not super. The S-HST is servo controlled so the pedals are easier to push and operate smoother. Instead of the hydrostatic swash plate being controlled directly by the pedals like the HST, the pedals operate a hydraulic valve which then operates a hydraulic servo cylinder to move the swash plate. Kind of like a hydraulic power assist for the pedals. I think the filter for the S-HST is orange and has a machined aluminum base with a larger hole.

Thank you for that information and yes, the filter is orange.