NH #3930 PTO HAS QUIT

   / NH #3930 PTO HAS QUIT #1  
Joined
May 10, 2008
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Purchased a clean, low use NH 3930 last month. Bushogged approx. 40 acres - no problem. Started mowing hay using a NH 450 sickle bar mower yesterday. Mowed about 14 acres and PTO quit. No noises, no clunks or knocks - just stopped. Called tractor friend and he suggested the problem might be a blown fuse. When looking for fuses (I do not have a manual) I found a switch near PTO connection. Tractor friend came by this morning and said switch needed to be in third position for mowing and I had probably burnt out the PTO clutch. Does this sound familiar to anyone? It seems to me if position of switch is that important it would have been decaled, labeled or something and new 3930 owners would be burning up clutches from coast to coast! Any ideas or help? Has anyone else experienced this problem? Needless to say, the thought of having to replace PTO clutch has not made my day. Thanks for any ideas.:eek:
 
   / NH #3930 PTO HAS QUIT #2  
I'm going to take a totally dumb-_ss approach to talking about this because I don't know your particular tractor at all. I feel your pain, but I have to agree with you. It doesn't sound that serious to me. Is your PTO like mine??? ie: Off or On?? I'm confused when you say the 3rd position???? Can you describe your options for your PTO? It sounds to me like it should have an electronic switch that tells it to turn the PTO on or off. If so I'd check under there for a switch then i'd check to see if the wires to that switch are pulled off or broke somewhere. If not, I'd take an ohm meter or a continuity light and unplug the wires to it then test the switch with it still on the tractor for continuity when it's in the "on" position. The switch could've gone bad.

Is your PTO light on??? If not, i'd check a fuse also as well as the switch. You may not have found the right fuse. If the light is on your switch is probably good and working. If that's the case check to make sure your PTO isn't actually working but you may have a shear pin broke in your drive shaft. Take the shaft off and see if your PTO shaft from the tractor is turning. Good luck!!!!
 
   / NH #3930 PTO HAS QUIT #3  
P.S. You may also have a safety switch on your seat that turns off the PTO if you're not sitting in it. You might check that also. Just a long shot.
 
   / NH #3930 PTO HAS QUIT #4  
If your 3930 starts, forget about the electrical system. The switch near the lever is a PTO neutral safety switch, nothing more. There is no seat switch or any other electrical component that would interrupt or disable the PTO. The easieat thing you can do is to check the hydraulic oil level in the rear axle housing. There should be a dipstick accessible from the rear of the tractor located just in front of the left rear axle housing. Add New Holland 134D hydraulic oil or its equivalent to the full mark. The transmission is a separate reservior. Does the 3 point hitch operate normally?
 
   / NH #3930 PTO HAS QUIT
  • Thread Starter
#5  
I posted a previous reply but I don't know where it went so if you have read this before just mark it up to my newbie-ness to message boards.
Now for my other bad information. I was relaying from the field (my only excuse). The switch is as you said just a button type to keep the tractor from starting with the PTO engaged. Second, the manual lever that engages the PTO had a small amount of rust so was only being slid halfway down the slot that engages the PTO. Could this have damaged the PTO clutch? The three point hitch seems to be O.K. but the fluid in the rear tank is at the add mark. I will add fluid and report back. Thanks again!:confused:
 
   / NH #3930 PTO HAS QUIT #6  
Your tractor has a hydraulically activated multiple disc wet PTO clutch. The fact that the 3PT works tells me the driveline to the PTO clutch and hydraulic pump that supplies oil to the clutch is OK. Whether or not having the PTO lever partially engaged has caused damage remains to be seen. Oil at the add mark should allow for normal hydraulic function when the tractor is sitting level, but top it off anyway. Be sure to pull the dipstick, wipe it, refit it in the tube, then check the level. On that tractor, oil can be forced into the unvented tube and be held there, giving a false (high) level reading if you just pull the stick and read it.
 
   / NH #3930 PTO HAS QUIT #7  
If it wasn't fully engaged.. I'd be worried about it.

I know the manual on my 7610s says to not hold the pto shifter partially in/out for more than 1-2 seconds for soft spin up.. etc.. or damge to the 'mechanism' ( I'm guessing clutch ), can result.

soundguy
 
   / NH #3930 PTO HAS QUIT #8  
My tractor has a safety device fitted where as if the mower hits a tough patch it disengages the PTO so that it wont stall the engine . It cannot be re engaged until you move the tractor and then apply the park brake .
 
   / NH #3930 PTO HAS QUIT #9  
I think a slip clutch might be better.. but....

soundguy
 
   / NH #3930 PTO HAS QUIT #10  
I should have explained better . This only happens when engine revs get down to around 200 revs , at the last second it will disengage the PTO to prevent a stall . We still rely on a slip clutch or belts to take out the shock loads . If it has the same electro system it may be something to look at , check that the park brake is on or maybe check that the PTO pulse sensor wire at the rear of the tractor has not been knocked off .
 
 
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