Removing PTO driveshaft from RC

   / Removing PTO driveshaft from RC #1  

Pooh_Bear

Platinum Member
Joined
Jan 2, 2005
Messages
739
Location
Dunlap TN 25 miles north of Chattanooga
Tractor
Early 1949 Ford 8N
I have an old abused rotary cutter (brush hog).
I have no idea what brand it is. I has been painted all red.
I am wanting to remove the driveshaft from it and use it on something else.
Normally I would expect a shear pin holding onto the gear box.
But this has something like a set screw. But it is more like a 1/4 inch bolt with a square head on it. Or rather it had a square head on it. I took a wrench and tried to remove it and the head broke off. All that was left was the threaded shank sticking up.
Ok, so I found a nut that would screw onto what was left of the bolt.
Screwed it down even with the top of the bolt and welded it in place.

Ok, so how should I proceed from here.
I'm afraid if I just try to turn the nut, the bolt will snap off flush with the yoke.
I was thinking of heating the yoke to expand it, then remove the "bolt"

Isn't there a trick of some kind where you heat it and spray it with WD-40
and it wicks the oil down into the threads to help remove it.
Seems like I remember reading something about that here somewhere.

My RC hardly gets any use. And I need the drive shaft for something else.
When I put it back on the RC I will use a shear pin.

So how do I get this "bolt" out without doing any more damage.

Thanks.

Pooh Bear
 
   / Removing PTO driveshaft from RC #2  
For starters, dump the WD40 and buy a can of PB Blaster at your auto parts store. Spray the threads liberally over several days, if you can wait that long. Then I'd use a punch on the bolt and give it a real WHALLOP downward to try to break it loose.

You might end up breaking it off. If so, proceed with a drill bit and an easy out. Worst case, you drill the old bolt out completely and have to re-drill and tap a different spot.

My guess is that there is a keyway in the shaft, and the setscrew sits on top of the key to hold it all together.

Ron
 
   / Removing PTO driveshaft from RC
  • Thread Starter
#3  
I don't think there is a key. Unless it is a woodruff key.
I can't see a keyway on the end of the shaft.
I'm thinking the end of the bolt goes into the hole where the sheer pin would go through.
The yoke is not tight on the shaft. It can wiggle a bit.
I can't understand why a RC wouldn't be using a shear pin.

Pooh Bear
 
   / Removing PTO driveshaft from RC #4  
Is the end of the coupling open on the u-joint side? You might have to break apart at the u-joint and look up in there to see if coupling has key slot. What were you planning to use this shaft on? Does it have the same coupling/shaft diameter, splines, etc.
 
   / Removing PTO driveshaft from RC #5  
Pooh_Bear said:
I can't understand why a RC wouldn't be using a shear pin.

Pooh Bear
It doesn't sound like you are the original owner. Based on that theory, who knows what a previous owner did to it. Maybe they broke the shear pin and replaced it with a bolt.
 
   / Removing PTO driveshaft from RC
  • Thread Starter
#6  
Nope, I'm not the original owner. It came with the tractor.
I don't even know what brand it is. Sure is heavy tho.

I can see the gearbox shaft. I'll look again for a keyway.
I don't remember seeing a keyway on it. Been a while since I looked.

What am I using it for:
I got one of them cheap little 1/2 HP clear water, water pumps from Harbor Freight.
The motor on this thing is severely underpowered. Gets real hot when running.
And where I want to pump water from is too far from the house to run electric.
I tried running the pump off an inverter hooked up to the tractor battery.
But I had to run the tractor (8N) at full throttle so the alternator could keep up.
I got to looking at the pump and motor, totally enclosed fan cooled motor.
So I removed the cover off the back of the motor, and removed the fan,
and replaced the fan with a lovejoy coupling.
I fabbed up a belt and pulley transmission to drive the pump motor at the correct RPM off the PTO of the tractor at idle speed. I just need the driveshaft to hook up the belt and pulley transmission to the PTO on the tractor.
Then the tractor can sit and idle while I pump all the water I want.

The electric motor is 2800 RPM.
Engine idle speed is 450 RPM making PTO idle speed 200 RPM.
200 RPM run thru a 1:14 step up transmission makes 2800 RPM.

Belt and pulley transmission is in two step ups.
12 inch pulley to 3 inch pulley, then 7 inch pulley to 2.5 inch pulley.

All I need now is that PTO shaft.

Pooh Bear
 
   / Removing PTO driveshaft from RC #7  
Hmm.. I'm thinking there must be a keyway, if this is a smooth shaft and yoke. Certaintly a 1/4" bolt would not be enough to hold a smooth shaft to a yoke, under heavy work load. I see 4' and 5' mowers pop 7/16 and 1/2 bolts all day... So.. perhaps check the rear of the yoke for a keyway slot.

If the yoke is loose on the shaft, and our guess is right about the 1/4" bolt being a keeper for the key.. you may be able to use a gear puller, and just pull the yoke off.. It's likely the stub of the 1/4 bolt holding the key will just shear and let you disassemble...

Soundguy
 
   / Removing PTO driveshaft from RC #8  
If you can, post some pictures. I suspect that that would help everyone come up with some better ideas.
Bob
 
   / Removing PTO driveshaft from RC #9  
Yep.. this is deffinately a place where a pic is worth a thousand words.. etc.

Soundguy
 
   / Removing PTO driveshaft from RC
  • Thread Starter
#10  
It rained all day today. Supposed to be clear the rest of the week.
So maybe tomorrow I can take a look at it and get pictures.

I may have just missed the keyway. I haven't looked in a while.

The other holes (not tapped) in the yoke look like they take
a 7/16 bolt thru the whole yoke for a shear pin.
These holes are at a right angle to the threaded hole.

Pooh Bear
 
 
 
Top