I think the drain plugs 17m mn mine but not sure. I know its a metric. Get a ratchet and set it to unscrew, things can get get confusing upside down under a tractor. Get a cheater pipe in case the drain plugs are tight. I use a 2 and a half foot pvc pipe. I usually run the tractor just one minute to help warm up the oil so it flows out faster. When you undo the drain plugs sometimes there is a washer there on them. After warming the tractor I usually take off the oil filter first, can be tricky as Kubota hides it down in there behind the loader. Have LOTS of paper towels handy. Put some clean oil on the rubber seal of the new filter and tighten it just with your hand.
Now make sure the tractor WILL NOT MOVE. Get under there with your ratchet set to unscrew a bolt. There is always two on my Kubotas. Drain them out and wait a bit. Replace plugs without using the cheater pipe. Just with the wrench or ratchet. Wipe all the grim you can from around the fill plug and the dip stick. Kubota's specs are at the VERY low end of what the engine will hold. Fill the engine using a clean funnel. Check dipstick often to make sure your not getting it over full. Replace plugs and take off. Check the oil level later and top off if needed. I'm severly disabled and in a wheel chair and I change all the oil and transmission fluid in my 4 Kubota's myself. Just make sure you have plenty of time and daylight. Its really very easy. Make sure you use a diesel oil.
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