Been there, done it several times. I nursed one (JD STX 38) for several weeks in a vertical position with ATF/Acetone mix. Kept puller on, hammered, pressed with two hydraulic jacks, etc but eventually wrote the rim off, cutting it off the axle with an angle grinder. Unfortunately I do not have an air chisel which in future I may try. Lately, I do not bother to try it in position. I just split the gearbox, take wheel and shaft out and press it off in a hydraulic press. These were all John Deeres with square key on a round axle. I have seen pressures in excess of 20 tons in the press before they would budge. Since these axles are not tapered, after the initial snap, they still have to be pressed all the way, Snapping as the release, all the way.