John Deere Hygard hydro/transmission fluid?

Not sure of mixing. Hyguard is not what I've heard used. Deere's hydrostatic fluid is thicker then type F thinner then hyguard. Supposedly guys have been using it too tighten up their converters when racing. It is not hydraulic oil, it is the fluid they use for hydrostats where the hydrostat has it's own resevoir separate from the hydraulic system on John Deere combines. We are thinking about trying it in our 9" turbo action 5k converter on the street... but have not tried it yet.