I swear people overthink this way too much. I would wager your best bet is that you just change the fluids regularly. Nobody has had a failure from running OEM or a reputable brand on the recommended schedule.
Thanks for your recommendation. Do you think this AUPT product is too thin?I would just run their severe gear 75w-90 in the rear. For the front I run a j20c from tractor supply as recommended by the manufacturer (Hilliard).
I've seen J20D (John Deere low viscosity Hygard) recommended for this application. I thought regular Hygard (J20C) could potentially cause the front drive to engage on its own. However, sounds like the J20C works too.For the front I run a j20c from tractor supply as recommended by the manufacturer (Hilliard).
Thanks for the recommendation. Good to know that fluid is an option.I'm not a scientist, just know that it's working for me. https://www.tractorsupply.com/tsc/product/traveller-universal-tractor-trans-hydraulic-fluid-2-gal is what we run in front diff.
J20D is better for cold climates.