Woods Blower keeps snapping grade 5 bolts

[KanakaRick]

Bought a woods blower a couple of years ago for my 50hp Kioti and it works like a dream, but recently it has started snapping the grade 5 shear bolts. I can hand turn the auger and then I will turn on the pto, and it instantly snaps the shear bolt. I was working great the week before, but now it is snapping shear bolts. I figured maybe I needed to have the pto drive shaft straight out from the auger u- joint, and then I turned on the pto and SNAP! I have no idea why it is snapping the grade 5's. I bought some grade 8's but I am hesitant to use them for obvious reasons. Any ideas?

 

[newbury]

Maybe try a different brand of grade 5's.

 

[LouNY]

Pop the auger drive chain off and see if you still snap shear bolts,
could be the impeller.

 

[rScotty]

The traditional cure for that is to engage the PTO clutch more slowly. But lately some tractor manufacturers have been replacing the PTO clutch with a simple on/off switch. The problem then is how to slow down the engagement.

Is there room to add an adjustable slip clutch between the PTO output and the drive to the blower? That would fix the problem.

I've never used one of those slip clutches myself, but they are common slip on units for PTO shafts & and not expensive. It's good to have one to protect the PTO internal gears anyway.
good luck,
rScotty

 

[JJT]

Are you starting the blower at full rpm? If you're easing into it at an idle, it should not be breaking shear bolts. I would not go to grade 8.

 

[KanakaRick]

nope, just at idle.

 

[KanakaRick]

Pop the auger drive chain off and see if you still snap shear bolts,
could be the impeller.

I can turn the impeller with my hand, so it doesn't have any rotating issues.

 

[KanakaRick]

The traditional cure for that is to engage the PTO clutch more slowly. But lately some tractor manufacturers have been replacing the PTO clutch with a simple on/off switch. The problem then is how to slow down the engagement.

Is there room to add an adjustable slip clutch between the PTO output and the drive to the blower? That would fix the problem.

I've never used one of those slip clutches myself, but they are common slip on units for PTO shafts & and not expensive. It's good to have one to protect the PTO internal gears anyway.
good luck,
rScotty

it's a 2002 Kioti, and i have no idea about slip clutches.

 

[KanakaRick]

Maybe try a different brand of grade 5's.

That's what I was thinking. The tractor is at idle, and as soon as I turn the button on that turns on the pto, the bolt snaps. A couple of days ago, it worked fine, but now I have no idea. After the bolt has snapped, I can turn the auger with my hand, so there isn't anything in the auger that would prevent it from turning.

 

[RoyJackson]

Easiest thing is to try another brand pf Grade 5 bolts.
It's an unfortunate fact that there are counterfeit bolts...lower grade then what's advertised or marked on the head. Very serious problem with Grade 8's, but that isn't limited to the harder grades.