how to drill out stuck PTO shear bolt?

[2manyrocks]

I'm wondering if you had tried to back the bolt out before you ground the head off. If not, you could try (if you have the capability) welding a nut on the end of bolt and backing it out. If the other end of the bolt is close enough, you could try the same thing there.

The continuing struggle with shear bolts is why I purchased a clutch, put a grade 5 bolt in place of the shear bolt and haven't looked back.

The bolt had enough bend in it that it wouldn't back out, either.

If there was ever a good sales pitch for buying a slip clutch, my experience fighting this bolt to remove it might be one.

 

[jccndakota]

As mentioned, flood both sides with PB Blaster or equivalent. I keep a spray can under the seat next to the wasp spray. The remaining part is probably bent now. Working it back and forth with an air hammer shouldn't cause a problem as long as it's lubed. Or as the guys said, mow until it's completely sheared. I lube the bolt shanks with anti-seize when installing new bolts to help with future bolt removal. Please let us know what works.

 

[jmc]

Please let us know what works.

See post #14.

 

[DarkBlack]

So a half inch grade 5 bolt has a single shear of 6300 to 8100 ft. lbs.

10k-14k Lbs according to your chart.
I have that same chart

 

[DarkBlack]

FWIW, I use gr 2 bolts, but decided to try a gr 5 after reading here. The gr 5 bolt broke on both sides, but one end of the bolt was long enough it cut a groove in the cast iron PTO end. I promptly went back to gr 2 @ $1.55 ea. including Nylok nut..

So, you use a shorter grade 2 bolt than the grade 5 you tried?

 

[jmc]

10k-14k ft/lb according to your chart.
I have that same chart

I didn't see that chart but suspect any reported shear ft-lbs would be torque around the bolt's axis, like with a wrench.

Torque to shear a bolt in this PTO setup would only be PTO torque, and would have to also specify the distance between the shear plane and the shaft centerline. That would work out to pounds force, not foot-pounds.

 

[DarkBlack]

I didn't see that chart but suspect any reported shear ft-lbs would be torque around the bolt's axis, like with a wrench.

Torque to shear a bolt in this PTO setup would only be PTO torque, and would have to also specify the distance between the shear plane and the shaft centerline. That would work out to pounds force, not foot-pounds.

Sorry, I meant Lbs. not ft/lbs. I corrected it.

 

[RayIN]

So, you use a shorter grade 2 bolt than the grade 5 you tried?

Same length,just softer bolt. I want the easiest to replace, cheapest part to be the first to break.