History of Tractor Hydraulic Fluid

90W is what I grew up with. Dad used it in our H and JD 60. The "new fangled" 460 Dad got uses Hy-Tran. Someone check me on this, but I believe the -60 series Farmalls were the first to go 100% UTF in the IHC product line. The -60s appeared in 1958.

I often raise my eyebrows whenever I disconnect a remote cylinder hose from the 460 after working it a while. Inevitably very small amounts of fluid escape when decoupling. That warm fluid hasn't much viscosity at temperature. Just wonder how it provides adequate film strength for the gear teeth. Obviously it must work OK.

Dad worked for an asphalt paving company. Apparently some of the equipment he was around required 140W gear lube as he had a couple of pails of it on his company truck. Man, that was some thick, nasty smelling stuff. The truck's bed always reeked of that gunk.

The universal fluids are not all that good a fluid. They try to meet the many specifications, all of which are different, some of which are contradictory. It's generally not as a good as the true specific correct fluid/oil. And in some cases, it's really not as good.