Which transmission oil is best?

[PatRarick 1]

I have seen so many different recommendations that it only gets more confusing. With the same model of Sundstrand, I have seen recommendations for Dexron, Type F, hydraulic oil, and even one that called for straight SAE 30 in the summer and Type F in the winter. It all seems to depend on what the tractor manufacturer or service manual publisher feels comfortable with. Maybe someone else can answer your question. I sure can't. Pat

[sask 0]

I have always used the same hydraulic/transmission combination oil that I use in my larger Massey 65 in my garden tractor hydrostatics as well. This includes both Sunstrand and Eaton pump equiped units. I initially did this out of ignorance because I didn't have any manuals when I first obtained them, and it seemed like a good fluid to use. They have worked fine this way for all the years I have owned them.

[SimpleMan 8]

Everyone. With the discussions that I have read in previous posts about hydrostatic transmission fluid, I've had to ponder the following. Which is the best fluid to put into the hydrostatic transmission of these tractors. I'm especially refering to those models which seem to be perfectly fine with either a 'hyraulic/transmission fluid', or running 'Automatic Transmission fluid'. If I look in my owners manual for my tractor, it states that I should only use "Simplicity hydraulic/transmission fluid" (of course it would). However, in the repair manual (Simplicity repair manual for Large Frame Garden tractors), in the repair section for hydrostatic transmissions, it states that I can use either 'hydraulic/transmission fluid', or AT fluid. By this...I would think that either is good. After all of this...the question is. Which one is better, if any? Why? Thanks all. SimpleMan