Deere 316k front pto siezed
Posted November 16, 2011 - 12:07 AM
After some panicked moments, trace it down to the front pto frozen solid. The rotor is frozen to the field coil/back plate. With the pto assembly removed, the engine runs fine... Note, it's not stuck because of being energized (different part), it is frozen with or without power - even out of the tractor!
So am trying to get the pto apart to see what is wrong with it. I can't get the rotor to come loose from the back plate/field coil. The driven plate (where the pulley mounts to) came off fine and the bearing on that assembly is ok.
Anybody have a similar problem or have any ideas how to get them apart?
Got them soaking overnight and will go at it tomorrow. Worst thing, I tear them up and have to spend the $200 anyway (or buy used off, well you know where.....).
Deere parts doesn't show an inner bearing - just replace the field coil ($109) and/or the rotor ($109) as needed.
Posted November 16, 2011 - 12:22 AM
Posted November 16, 2011 - 08:29 PM
Got the two parts, well, apart....
The rotor has a shoulder that rides about 3/4 inch inside the field coil housing. This had friction welded to the field housing case. The resin of the coil looked fine - no distortion or heat marks evident.
Will try to get some pictures tomorrow. Also need to test the coil and see if it still functions - it was working ok before being parked...
It shut down fine - didn't quit - I turned it off... Evidently didn't fuse until after it shut off?!?!?!
Wondering if some trash or something got in the space and forced the rotating parts together, starting the destructive cycle? Or could it have been caused by being out of adjustment somehow? So now I know WHAT happened, just still not the WHY...
If everything works ok, will chuck it in the lathe and turn the burrs off and burnish the adjacent surfaces.
- MH81 said thank you
Posted November 17, 2011 - 07:45 PM
Posted November 18, 2011 - 11:16 AM
Springs have a little bent down toward the armature late, but that shouldn't make it sieze?
As promised, here are a few pictures...
Posted November 18, 2011 - 06:49 PM
Posted November 18, 2011 - 07:40 PM
Posted November 18, 2011 - 07:53 PM
Posted November 19, 2011 - 03:10 PM
Runout on the crank was within specs, so I don't think that is the issue. Didn't consider that the mount may have been off a little - will check it when I mount it back up.
Did find something strange though. When I put it in the lathe, the rotor was out of round - can clearly see where the "high" lobe was, and that was where it was hitting as it spun. I set it up a couple times and trued it on the bore (as opposed to the shoulder) and the results were consistant. Not way out, but enough to rub - that would also explain why it didn't sieze while running, only hitting about 15 degrees per rotation so the motor could "power through it."
So maybe everything was just lining up "wrong" -tight field core tolerance, had the mount off a little, the rotor out or round, and it hit on the high spot as it stopped and siezed. Only thing I can think of....
So, in retrospect, I learned some new stuff, I THINK I know what and why happened, and I didn't have to spend any money!!!