I know I work at a John Deere dealer as a mechanic, and you wouldnt believe the number of clutches that are on some of these tractors, with a powershift transmission on an 8000 series you can have 8 or 10 separate clutchpacks when you start counting the pto and mfwd. They are the same design as in an automatic, I have been into both of themI would see absolutly no problem with running Hygard in automatics, the only problem i could see is in severe cold climates that it might not flow enough till it gets warmed up, but they also have a low-viscosity hygard that is designed for lawnmower hydrostats and can be used in tractor transmissions below a certain temperature also.