I went on the hunt for tractor hydraulic oil 2010. Was running JD and the price got way to high for me. Switch to McCormick and dealer went out of business. Then found Mobil Fluid 424 in my area from a Exxon distributor Price started out reasonable and in 18 months it was $92 per 5 gal. pail.
Read on another tractor site that Cat dealers in my area carry Mobil Fluid 424. E-mailed the supplier for Carter Cat in my area and got a quote for $62.85. I'm happy. They stock about 50 pails and it's there when I need it. I use it in a Deutz Fahr agrofarm 100. Wet clutch, shuttle, front dif. and hubs use the same oil. It's a little heavier oil than JD but it's done great in my Deutz.