Stuck PTO shaft saga

[Mathias NY]

I've come across 2 pretty bad examples.

About 4 years ago, my dad was attempting to remove his 3pt flail mower from the tractor and discovered the shaft would not collapse. We chained the shaft between 2 trees and with 8000 lbs of winch, we were able to pull it apart. The culprit was metal on metal gauling. Basically, it didn't get anough grease, so friction caused the metal to weld itself together. The shaft had to be replaced.

About 20 years ago, a farmer that I used to work for had the same issue with a pull behind rotary mower. As he was turning at the end of a row, the PTO shaft on the mower seized and pulled the shaft out of the tractor. Both shafts had to be replaced.

The moral of the stories: Always grease your PTO shafts!

 

[nickel plate]

Thanks for the tips! I will check for any retaining rings/clips, etc, but I think I have a different problem, as somehow after the shear pin broke, the shaft went further onto the gearbox shaft... need to get some pb blaster in there for a few days and try prying some more.

deezler,
Look up your model King Kutter rotary mower parts diagram and see if there is a retaining ring. My guess is there will be one.

 

[MissouriSprayer]

What is the worst case of a bound up PTO shaft anyone has had? I had mine
today.

I picked up an older Brush Hog brand cutter awhile ago, and decided to test it out today. When I tried to hook it up, I discovered the PTO shaft was stuck in the collapsed position. I've had this happen on older equipment, so I attached one end of the shaft to my pickup, ran a chain under the belly of the tractor, and backed away, thinking I could pull the shaft out.

No luck: the tractor just spun, even with the differential locked. This kind of surprised me, because that was a substantial pull. I sprayed penetrating oil around the junction, and tried walloping the shaft to collapse it more. Frustrated, I decided to quit fooling with it and just pull it apart. I blocked the tires of the pickup, set the parking brake in 4 wheel drive low range, and chained one end of the PTO shaft to the hitch. I pinned the other end to my IH 464, certain I would just ease the two halves apart.

Nope. The tractor ended up spinning the tires and the shaft never budged. At this point I was starting to get concerned: the 464 weighs 5100 odd pounds naked, has filled tires, and had a heavy disk out back, so is approaching 7000 pounds with me on it. I didn't want to "bounce" at the end of the chain, since I was afraid of damaging the pickup.

In desperation, I rigged the shaft onto my 20 ton press with some chain and arbor plates. While it obviously wasn't 40,000 lbs of force, I ended up bending some links on my 5/16" Grade 70 chain at the same moment when, with a loud bang, the tubes finally slipped apart and a cascade of black rust-water sprayed everywhere. I cleaned the tubes, sand blasted the sliding surfaces, regressed, and it slides freely and smoothly. I'll end up replacing the U-joint crosses after this fiasco, but remarkably, they didn't show any signs of damage, and were free moving and smooth.

So, who else has had a severely frozen PTO shaft, and what sort of Rube Goldberg apparatus did it take to get it apart?

Mine went into a dumpster and the new one works like a charm. Now I have a down link on three point, the one that is adjustable....well if it would turn it would be. Ive heated, pounded, soaked in oil, used more heat and bent a cheater bar on it.

No joy as of yet.

 

[deezler]

deezler,
Look up your model King Kutter rotary mower parts diagram and see if there is a retaining ring. My guess is there will be one.

Yep, there's definitely a retaining ring groove, no ring present though. You can also see the shear pin sitting in it's through-hole on the gearbox input shaft, and how much further the PTO shaft coupler has been pushed onto the mower gearbox input shaft.

A co-worker of mine had a theory that the shaft may have been too long for the tractor it was being mounted to, such that when they lifted the 3-pt arms, it busted the shear pin and pushed the coupler further onto the mower, since the shaft could not collapse any further. This might also explain why the shaft was totally jammed stuck in it's shortest position.

And here is all we were able to accomplish by pushing the PTO shaft coupler onto the tractor PTO output shaft... not good enough. As I don't have a sandblaster, I guess some more time with a wire brush & file will be required.... ugh.

 

[KubotaSam]

Yep, there's definitely a retaining ring groove, no ring present though. You can also see the shear pin sitting in it's through-hole on the gearbox input shaft, and how much further the PTO shaft coupler has been pushed onto the mower gearbox input shaft.

A co-worker of mine had a theory that the shaft may have been too long for the tractor it was being mounted to, such that when they lifted the 3-pt arms, it busted the shear pin and pushed the coupler further onto the mower, since the shaft could not collapse any further. This might also explain why the shaft was totally jammed stuck in it's shortest position.

And here is all we were able to accomplish by pushing the PTO shaft coupler onto the tractor PTO output shaft... not good enough. As I don't have a sandblaster, I guess some more time with a wire brush & file will be required.... ugh.

I wonder if their is some way to rig up a slide hammer type of arraignment. Could you weld a nut temporarily to the end of the shaft, use the slide hammer to remove the shat from the mower then cut or grind the nut back off the shaft.

 

[284 International]

Deezler, have you checked to make sure the retaining pin in the female end of the coupler is moving all the way clear of the splines? It looks like the coupling is sliding on to about that point; if that retainer won't move, you'll never get it on.

It really looks like that shaft is wedged into the bore of the coupling by that sheared off bolt. I would wrap the gearbox with a chain and fasten it to something solid, run another chain through the U-joint, and try gently pulling it apart, whether with the tractor, a winch, vehicle, etc.

 

[deezler]

Deezler, have you checked to make sure the retaining pin in the female end of the coupler is moving all the way clear of the splines? It looks like the coupling is sliding on to about that point; if that retainer won't move, you'll never get it on.

It really looks like that shaft is wedged into the bore of the coupling by that sheared off bolt. I would wrap the gearbox with a chain and fasten it to something solid, run another chain through the U-joint, and try gently pulling it apart, whether with the tractor, a winch, vehicle, etc.

Thanks for the reply. Yeah, we did make sure the retaining pin was moving freely. It was not at first, horribly corroded and stuck. We had to generously douse it in lube and hammer it around for a while. Our basic assessment was that the coupler was not even quite getting far enough on the tractor shaft for that retaining pin to be an issue. But it's definitely kind of tricky to hold the pin out of the way while still applying maximum force to slide the coupler onto the tractor. Then again, it probably shouldn't require that much force in the first place, eh? I may try to spend some more time with it tonight or tomorrow.

And yeah, I think some serious force may need to be applied to get that coupler off the mower gearbox shaft. I think I'll try the heavy ratchet-strap tugging method again (same as we used to extend the stuck telescoping PTO shaft). But actually, it took all our might cranking the ratchet just to extend the shaft, and the coupler on the mower didn't budge... so something more powerful may be required. Chaining the mower to a tree and gently pulling with the tractor might be a good idea.

Another question - as we couldn't figure out how to get the PTO shaft guards off easily, we ended up accidentally breaking them and then cutting a bit to get them out of the way in order to look things over. How dangerous is it to operate a PTO shaft without the flimsy plastic guards in place? Are they really doing much? Obviously a catastrophic shaft, coupler, or u-joint failure would not be well contained. But I am not too worried about putting hands/limbs anywhere near the rotating shaft. But of course, dirt is going to get right into the moving / lubricated parts, so that's not good....

 

[284 International]

How dangerous is it to operate a PTO shaft without the flimsy plastic guards in place?

Answers will range from nothing to marvels at the fact you have lived. It's a passive safety device: how dangerous is it to ride a motorcycle without a helmet? It only might save you, though it inarguably can and has in some cases. Like a helmet, nobody plans on needing or using a PTO shaft guard. It is indisputably safer to have them than not.

Having said that, I've got implements without them, and implements that do. I recognize the added risk, and accept it. That doesn't mean I would tell anybody else to do so. I think that confidence in one's ability to avoid injury is one of the greatest risk factors in causing people to get hurt on or around equipment. The numbers of operators with decades of daily use of their machines who get caught up in PTO shafts or rollover accidents are staggering.

Even small tractors can snag clothes, shoe laces, hair, or whatever else, and cheerfully beat someone to a lifeless pulp while idling. Be careful, and let us know how your disassembly goes!

 

[nickel plate]

How dangerous is it to operate a PTO shaft without the flimsy plastic guards in place? Are they really doing much?/QUOTE]

Just a recent observation:
I went into town to get a couple of propane bottles filled at one of our several equipment rental companies, was second in line so while waiting my turn I walked over to look at the rental tractors, all of which were in the 25/35 HP range and on one of them was a really beat up rotary mower without a "flimsy plastic guard" covering the now exposed PTO sliding shaft. It's perhaps one thing for a private party tractor owner to not elect to have a shaft guard but on a Joe Blow rental???? All I could think was CAL OSHA.

 

[deezler]

So the saga continues, at least for me and my piece of sh*t rotary mower acquisition.

I left the tractor sitting like this the other day, with the PTO shaft rammed onto the tractor PTO output as far as we could get it.

Now today, I go to remove it from the tractor, and it won't freakin budge. Great. Had to remove the PTO guard so that I could get my 2 lb hammer in there. Finally it starts moving and comes off.

So. Next step, get that d@mn shaft off the mower gearbox input shaft. I chained the rotary mower up to the only clump of tree trunk in my rental house backyard, then chained the shaft coupler to the tractor drawbar.

Like so:

After several light tugs and steady pressure from the tractor, the coupler had only slid about 0.5cm. WTF. Cranked up the rpm, engaged 4wd, re-fixture my chains on the shaft coupler, try some more. Even reaching a 4-wheel burnout briefly (oops). This thing is so stuck, I don't get it. It slid somewhat, so...? .... it's not totally seized up...? But what the heck is holding it on there still? The broken shear bolt is still wiggling around free in the mower gearbox input shaft hole, so it doesn't seem to be that. I can't see any other obstructions to simply sliding off the mower. There must be some other piece of metal somehow jammed between the coupler and the gearbox shaft. Or just enough years of corrosion to disloge material and bind things up.

Next plan is to get a TORCH and blast the pto shaft coupler. This kinda sucks. Being an asphalt farmer is tougher than I expected. Haha! :laughing: