Yesterday I hooked my 5240 to the diskbine.  I turned the pto shaft from 540 to 1000.  I engaged the pto and it started fine but shut off after about 20 seconds. My first thought was that the sleeve inside had not come back the whole way when I changed the shaft but I don't think thats the problem. Messed with it for a while and most times it would not engaged at all but once in awhile it would engage for a short time and then shut off.  When it shut off the lever stayed engaged, it didn't automatically fall back to the off position like it does when you shut the tractor off.  The other odd thing is that I can't get the shaft reinstalled in the 540 position....it won't push in far enough to get the snapring in.  Any ideas????  Most of the symtoms make me think some sort of hydraulic issue, but the shaft not reistalling makes me wonder of something in the gearing is messed up.  It has hydraulic oil.  I never heard any alarming thunks, snaps or grinding noises.