Thanks. The manual is still (to me) quite confusing on the matter. At 200 hours it calls for "Replacing Transmission Oil Filter (HST Type)". I think this is the one on the left side of the tractor by the step. But it points to three drain plugs: Two near the rear axle, and another further forward.
At 400 hours, ti calls for "Replacing Hydraulic Oil Filter" but only the two rear most plugs are called for draining. WTF?
WTF indeed! Something not talked about is how far out of date that the maintenance section of the Owner's Manuals can be. And also that sections of the maintenance schedule are more general than model specific. Crawl under your Kubota 5240 and take a look for those drain points... See if they even exist. That might just answer your question on drain points. I did it to mine and it got me to thinking about how I should put more mechanical thought into the maintenance schedule. Bottom line was not to Kubota's schedule as the final word.
My Kubota
M59 lists 4 different drain plugs that are to be removed to drain the HST/Hydraulic oil, but several of those drain plugs don't even exist on my tractor. I checked on a later
M59 maintenance manual and the error was still there.....which means the maintenance portion of my Kubota's Owner's Manual is general rather than particular to my model, and also at least ten years out of date. Your's could be too.
It does make sense to change the HST filter more often, and it also makes sense that the HST change interval would be a sub-multiple of the hydraulic filter change interval. The HST is more sensitive to small particles; you sure don't want that particular filter ever to go into bypass mode..... BTW, bypass mode settings and the filter's bypass valve construction are internal to the filter. And if that all by itself isn't a sufficient reason to stick with OEM filters rather than aftermarket then I don't know what might be.
The downside of a of a common sump is that the HST needs super clean oil, while the transmission's big rear end gears and differentials do tend to shed fairlylarge particles of hardened steel that can really mess up a HST. So that explains whey there are lots of filters and short filter intervals. I go along with that.
Something else to think about is that today's mechanical schemes for changing the filter without simultaneously changing the oil is a fairly recent innovation. For a maintenance person to keep the modern hi-dollar, long-lasting oil while only changing the filters makes sense today, but it didn't used to be so commonly done. That may be another way that the maintenance part of your Owner's Manual isn't up to date.
Enjoy,
rScotty
