Bush hog shaft frozen

[handirifle]

So my neighbor approached me a week or so ago. Says he has this 4' bush hog that he has not used in years, and wonders if I want it, duh, of course.

Everything is in great shape, except, the drive shaft slip section is frozen. He told me it was but said with heat and a hammer it has always come loose before. Well I have tried heat, before and after penetrating oil. No luck. I tried "coaxing" it with a hammer and no luck.

I have sprayed the penetrating oil as much as I can and now this is two unsuccessful days at freeing it up, so here come my questions.

My first bush hog of any brand/type. Not a complicated machine, but looking at it, in order to remove the shaft completely it looks like I need to remove the snap ring on the gearbox yoke, and what I THINK is the shear pin about 3/8 or 7/16" dia. Does this just hammer out, and does it matter which side it goes out? Is it reusable if I do, or do I need a new one.

I am hoping I can take the shaft to SOMEONE that can force it apart. Once that is done I will clean both pieces and make sure it is well greased.

Suggestions? Anything else I should try? The PTO end is free, as I have not been able to compress the shaft to even try the darn thing out. Everything turns freely, its just the slip shaft, doesn't slip.

 

[RNeumann]

If it’s not bottomed out I’d try beating it together rather than apart. You have some leverage when compressing. It’s either going to come apart or you are getting a new slip yoke- not a big deal either way. Especially for a free hog.

 

[handirifle]

It isn't bottomed out, for sure. The yoke is welded to the shaft, wouldn't that require a whole new shaft? Nothing wrong with the yokes themselves, it's the main shaft that is frozen.

 

[Gunny]

They can be a real bear to break loose, I had one that I fought with that took a week, working on it for 15-30 minutes a day.

It would help if you could some tension on it with something like a cable winch. Chain the bush hog to a tree or something secure, run a small chain through the tractor end of the shaft so that it's pulling against the yoke, not a U joint.
Put some tension on the shaft, through some heat to it, wet it penetrating fluid, tap it with a hammer or use an air chisel for vibration. Let it sit, then repeat the next day.
Eventually it should come apart, but there's a chance it'll never come apart.

The quick and dirty way to do it is just get new shaft. If you've got the time and patience, you'll free this one up more than likely.

 

[shaeff]

Is there a grease fitting on it? Can you use hydraulic pressure from pumping it full of grease to loosen it up? (A Lock’n’lube adapter will be helpful here)

Aside from that, I’d try to hammer it together after heating the outer sleeve, or use a come-along or ratchet strap to pull it apart. Get some pressure on it, heat it, run an air hammer over it, etc...

 

[handirifle]

Its connected to the 3 point hitch currently, and was trying to avoid disconnecting, hoping I could free it up and run it, but it looks like that might not happen. At least like I envisioned it.

About the shear pin, is it just a friction fit? Could it be hammered out either side?

Worst case, I replace the shaft, how do I know what length to buy, since this one is stuck, I cannot measure compressed length, like I see on the internet.

I can measure from splined shaft to PTO while it is connected, should I do that just in case?

I know if I keep hammering on the yoke it will ruin where the Ujoint bearing cups go and the shaft will be useless then, so I am trying to avoid that.

 

[Gunny]

Do you have an air chisel? Don't hammer on the yokes, you'll wind up deforming them, then you're screwed. With an air chisel, you can apply the vibration direction on the part of the shaft that slips over the inner part.
It's a long drawn out process - over the years the shaft has formed rust down the length of the slip parts, by giving it some heat, vibration and penetrate you have to get the process working all the way down the shaft. It didn't lock up over a day or so, you're not going to be able to free it up in a few minutes

 

[jaxs]

Everything that's been suggested can help if shaft is simply rusted between halves but each remedy require's different approach,depending on type of shaft. If male half is a 3 sided hollow tube,you better understand "heat shrinking" before lighting your torch,you can ruin the shaft. http://https://weldingweb.com/showthread.php?47275-The-flame-quenching-heat-shrinking-straightening-bending-thread Instead,hang shaft so gravity pull's penetrating oil to far end. Leave hanging and periodiclly add oil for several days before attempting to separate. If male half is a solid square/rectangle piece,you are in luck. End on those can be cut off and replaced for $30 in parts. On this type,heat only 6"-8" where halves meet. That's the only area where halves contact one another.

 

[ruffdog]

As far as the shear pin goes, it should be a simple slip fit and should easily be tapped out. BUT...if the pin is partially sheared from use and and the yoke/shaft are froze up too, it will NOT tap out. Can you turn the shear pin to get some lube in there? The snap ring keeps the yoke on the shaft in the event that the pin gets sheared and should be lubed so it spins and moves freely.

 

[handirifle]

Ok will try to answer all. Yes I have an air chisel and will give it a whack. The shaft is a 3 sided one and the end of it is kinda beat up from PO and I prob added to it. Getting desperate.
When I hit the yoke, it is on the back where it is welded to the shaft.