I've got a Grasshopper 725 Kubota with the G2 transmission system and I can't seem to find out what type of hydro fluid to use in it. Yes, my dealer says use "Grasshopper part number so and so" but I really don't feel like paying $40+ for a gal of hydro oil. It's bad enough that they get $19.50 for the filter but I can't find a cross reference for it anywhere. I've e-mailed Grasshopper directly and asked for an oil spec but they haven't responded yet. Have any of you used a different hydro oil than the grasshopper part number oil? If so, how much and where do I find it?