5030, I agree with your take on the front axle and diff lubes.
But not the advertising. Come on now..... Call 'em like they really are. Chevron is fine, and so is UDT...but their advertising might as well be written by politicians. At least Chevron - probably - refines their own product. Kubota has it done by small time contract refineries and periodically gets a load of bad stuff.
The aren't any performance standards for trans/hydraulic oil. So there is no target to shoot at and no way for one oil to "beat" another. The only spec that exists is for the simplest form of flash point and viscosity....even though they all try to make it look like more than that. So just how does one product "beat" another on either of those?
I agree Scotty. I believe (not 100% sure) that Warren Oil produces Sudt for Kubota whereas Chevron refines their own. Chevron, being a commercial / industrial supplier really don't advertise their THF a lot and why it's kind of hard to get. Chevron don't 'hype' it al all. Just plainly states on the label it meets or exceeds the Kubota published specification for UDT and SUDT and nothing more and I'd bet that Chevron being as big as they are, they tested theirs and Kubota before putting that on the label.
One thing I do know from real world experience in the dead of winter up here and that is, the THF cold flows excellently and cold hydraulic response is very good. Not that I don't pre warm the cab tractor prior to moving snow, because I do, but I've never plugged it in, no matter how cold it is and it starts effortlessly with a pre heat of the glow plugs. Part of that I'm sure is I run well maintained starting batteries and change them out at least every 5 years and keep everything clean and corrosion free.
I always run commercial starting batteries with the maximum CCA I can get.
I agree but I also have 'real world' experience.
I believe Kubota (and maybe others as well) run hydraulic oil in the front assist axles just to not have to have another lubricant to deal with but again, real world experience in my case tells me gear oil provides better shock resistance and the specific additives in gear oil prolongs the life of those gears inside as well.
Years ago (I'd like to find the test article but I cannot, the now defunct EMD in McCook, Illinois, ran a first article test (they had a very extensive dyno testing facility) with ordinary hypoid geared axles. They ran one with just plain motor oil, one with no oil and one with hypoid gear oil (Shell btw) and ran them loaded to specification at a set rpm until they failed. The axle with the Shell (Donax I believe) gear oil outlasted the other 2 and when they took it apart, there was very negligible wear. That pretty much sold me on running hypoid oil in my front drives.