1086 pto

While round baling hay today my pto suddenly stopped turning, the bale was about full and I was about to tie it so the pto was under a load. It has always worked perfect before, I don't know whether the clutch came out or what. If any of you guys have any ideas what the problem is I would appreciate hearing them. Thanks

Is the PTO the only thing that quit? If you also lost power steering and brakes the failure is the PTO drive hub in the main clutch. Facing down hill with a low transmission oil level can also allow the PTO to draw air into the PTO pump and cause the clutch pack to release. If those things are OK the problem is in the PTO assembly or the control linkage. If the linkage is still connected does it still fell the same when engaging?

There is a small pin in the PTO control valve stem that can break. When that happens the stem will pull up with less effort than before. Will the PTO shaft spin with nothing attached to it? If not there is a good possibility that this pin broke.

Another possibility is that the clutch pack is worn out. There is a snap ring that restricts the total travel of the piston. When enough wear occurs so that the piston contacts the snap ring there will be less compression of the clutch pack even though the hydraulic engagement pressure remains the same. At this point a couple of seconds of slippage under load will be enough to destroy what is left of the clutch pack. In this case the PTO will usually still turn if engaged with nothing attached to it.

When working the lever it feels normal, no unusual noises, it will not turn by hand.

Only the very last 86 series had PTOs that could be turned by hand with the engine off. Up until the change all the PTO units had spring applies, hydraulic released brakes. If yours is the later style and it no longer turns by hand with the engine off it is a good indication of a burned out clutch pack. The other checks I mentioned as far as the shaft turning is to be done with the engine running and the PTO engaged.