I hear this stuff all the time. I use brand X oil or additive because it's good. Yet Kubota doesn't recommend any of them. Your owners manual and WSM will tell you what to use in it, and generally speaking it's gonna be Kubota branded stuff....so that tells us that Kubota has tested their equipment with their own fluids and is why they recommend it. 'Nuff said?
Wet clutch stuff. Motorcycles in particular (including ATV's and some side-by-sides) have special requirements in the lubrication department. Thus I don't care if you have a few million dollars worth of stock in some aftermarket company that provides the snake oil that you swear by, after almost 3 decades in the business specializing in ATV's, SxS's, and motorcycles, the one thing I have found is that you will not go wrong with what the manufacturer recommends for lubricating fluids...so if your Kawasaki recommends Kawachem 10w40, you'll likely find that your engine will perform better and work as designed by using what they recommend. I've seen quite a bit (but certainly not everything) and as a generality, out of thousands of clutch jobs and clutch complaints on wet clutch stuff, I'm gonna say about 100% of them were running some aftermarket engine lubricating oil and not the recommended fluid. And that's perfectly fine with me. I like selling my labor time when it comes time to replace the wet clutch in your Teryx4 or Viking or Rhino (especially like the Rhino's) or Fourtraxx. Don't bother me one bit, it's how I make a living and I enjoy doing it. Kawaski vulcan 1500/1600/1700 and some of the older Bayou 220/300/400 models seemed to be particularly notable with relation to clutch issues. Also all the Ninja series but those are usually rider related (60mph wide open throttle clutch dumps, etc). And a slew of off road stuff which is usually a combination of running too long on an oil change, abuse of the clutch, and use of the wrong lube oil (in transmissions and/or engines). Lot of guys like Rotella in their transmissions on the off road bikes and, well, as I said, that's fine by me......easy money.
Super UDT2 in the transmissions and front axles, 15w40 kubota in the engine, and it'll be hard to go wrong with that, which includes most of the RTV series, most tractors, most of the skid-steer's, etc. The WSM spells it out. Read and understand it, and follow it to the "tee".
