I have a '98 L3600GST and have been faithful to the service points but I do 100% of my own service. When I first bought the 3 five gallon jugs of Super UDT fluid at the local Kubota dealer, I nearly fell over at the price. I think I paid around $80/5 gallon jug. It was very stiff. But after reading the owner's manual and talking to the mechanics at the dealership I decided that was a right move. When I went back and hit my 400 hr. service interval, I stuck the with Kubota brand Super UDT fluid accepted it.
My thinking is that if I save $100 in hydraulic fluid and I destroy a seal, the repair will be out of my capabilities in most likelyhood and will be hundreds of dollars if not more. One crummy little seal can ruin your day especially if it comes at a time when you really NEED your tractor! So I accept the cost as part of the deal. I didn't buy a Kubota because I was looking to save money - that's for sure! I am now at 1000 hours and it's continuing to work flawlessly for me. The tractor gets some work in winter with snow management, a LOT of work in summer mowing on my farm and much of the mowing involves stabbing under trees with a rear discharge mower deck on the 3 pt hitch. I bought the GST for exactly that service. So it's gone from the coldest cold in snow to the hottest hot (100) all while I beat the crap out of the jockey shift and after 1000 hours it's as tight and responsive as it was when new. I attribute at least a part of that success so being faithful to the Super UDT fluid and accepting it's cost as part of the experience!
