PTO stuck on Rotary Mower

   / PTO stuck on Rotary Mower #1  

Rob 80

Silver Member
Joined
Aug 22, 2015
Messages
208
Location
WVA
Tractor
B2650
Trying to fix dads B7800 it has a rhino rotary mower SE5 and the PTO shaft will not slide so i was going to remove it from the mower and clean it up with some penetrating oil, It's been giving him trouble for years. I was unable to get it to slide even pulling on it with the tractor. Could even be bent.

I removed the sher bolt that holds the pto shaft to the mower and it seems to have something else holding it. The sher bolt was actually bent so i need a new one.


Page 30 #8

If i can get the pto shaft off and the penetrating oil does not work i will just take it somewhere.
 

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   / PTO stuck on Rotary Mower #2  
With the shear bolt removed the shaft should slip right off. I suspect rust or corrosion is preventing this from happening. Try tapping with a hammer after applying penetrating oil. You may be able to get it to move a bit by tapping it further on a bit just to break the adhesion. It's also possible the area around the bolt hole has mushroomed out a bit next to the bolt hole. If this is the case you may be able to remove the mushroomed metal and bevel it down a bit with a drill bit larger than the hole through the shaft.
 
   / PTO stuck on Rotary Mower #3  
Had to remove one from my finish mower gearbox.
Ended up heating with a torch.
Just remember to regrease everything when finished.
 
   / PTO stuck on Rotary Mower #4  
I had a pto shaft get stuck on a finish mower. All the penetrating oil, heat and hammering only moved it an inch. I think the previous owner hadn't used it for years, and lack of grease allowed it to rust. Grass didn't stop growing so I finally got a new pto shaft at tractor supply, and the mower works fine now. If your shear bolt was bent, it may have been the wrong grade and allowed the PTO shaft to slightly twist when the mower hit something, making it really hard to get to slide again.
 
   / PTO stuck on Rotary Mower
  • Thread Starter
#5  
Where would i find the sher bolt?

HHCS 1/2NC X 3 PL2 MUST BE GR2 FOR SHER BOLT

Would tractor supply have it?
 
   / PTO stuck on Rotary Mower #6  
Where would i find the sher bolt?

HHCS 1/2NC X 3 PL2 MUST BE GR2 FOR SHER BOLT

Would tractor supply have it?

That's a very large diameter shear bolt, being half inch in diameter - although three incles for shank length is about right. You can use longer if it doesn't foul anything. But, are you sure of the 1/2"diameter? The reason I ask is for an ol
5 foot bush hog on a 50 hp tractor our shear bolts are more like 5/16" in diameter, not 1/2".
Any hardware store will have grade 2 bolts threaded for NC - which is simply "National Course" thread as opposed to find thread. That spec is the softest (and cheapest) grade of grade of bolt and will not have any radial slash markings on the head.

For consistent shearing, the best way is real shear bolts with a long smooth shank and shorter threaded area so that the part of the bolt shank that goes through the PTO shaft is unthreaded...i.e. smooth. That way only the threaded portion of the bolt sticks out. Use a Nylock nut or smash the bolt threads so that the nut does not come off.

But if you cannot find a bolt threaded like that, just go ahead and get one of the proper diameter in grade 2 that is threaded so that it will shear across the threaded area. Get more, because that way they will shear at a slightly lower torque.

Get a dozen or so, and as many nuts. No washers.
good luck
 
   / PTO stuck on Rotary Mower
  • Thread Starter
#7  
There was a C clip holding it on just so you know :)

apparently i have the wrong manual
 

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   / PTO stuck on Rotary Mower
  • Thread Starter
#8  
The part i found is listed at HHCS 1/2NC X 3 PL2 MUST BE GR2

But when i measure the bolt it's 3 1/2....am i missing something simple? :)
 

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   / PTO stuck on Rotary Mower #9  
3-1/2" is fine as long as the tail of the bolt doesn't strike anything. Just make sure it's a grade 2...and make sure that you put the snap ring back on.
 
   / PTO stuck on Rotary Mower
  • Thread Starter
#10  
3-1/2" is fine as long as the tail of the bolt doesn't strike anything. Just make sure it's a grade 2...and make sure that you put the snap ring back on.

I haven't been able to get the snap ring back on it's in a tight place. Do they make a special tool for them? I get it half way on then it snaps in the grass! :)
 
 
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