power steering fluid

I have a 7441. I bought this tractor used and I am in the process of changing all the fluids and filters as I do not know the history of the tractor.

My Zetor manual says "10W hydraulic oil meeting specification ISO 32 or 46"

When I show this to my auto parts guy he looks at me like a cow looking at a new gate.

Can anyone recommend a brand and what "exactly" I need to put in my tractor. I don't want to tear it up using the wrong fluid.

ISO VG46 hydraulic fluid is the same viscosity as 10w/30 STOU. You will find neither VG46 or 10w/30 STOU at an auto store, go to an ag or construction dealership.

These machines have the orbitrol steering, the older models with the power assist steering ram, dont get actuated in thick oil and ATF 2 is best.