Constantly breaking shear bolts on my cutter....help?

[Rock knocker]

Weird. I'd want to do that via a confirming e-mail

 

[smstonypoint]

Weird. I'd want to do that via a confirming e-mail

I've had by Bush Hog BH14 for nearly four years and have yet to break a shear bolt. I don't know how Bush Hog rotary cutters are shipped. If the PTO shaft is attached to the gearbox at the factory, I suppose I have a grade 2 bolt:confused3:


Steve

 

[Trophyduck]

You turn the PTO speed down as slow as possible - do you mean the tractor is idling? Is you PTO engagement an electro-mechanical engagement system? On my tractor I can "slip and feather" engagement with the PTO lever - just like the clutch on a manual transmission car. Electro-mechanical can be a fairly harsh, jarring, abrupt engagement system. These type system should be able to be adjusted by the dealer.

I don't say you necessarily need to use the OEM shear bolts but if you do not - whatever you are using should be the same grade.

Another answer would be as TractorNH indicates. Install a slip clutch, properly adjust it and instal a grade 8 shear bolt.

However - be advised - many PTO implements have Grade 8 OEM shear bolts. My Wallenstein BX62S OEM shear bolt is grade 8.

I'm using Grade 2 bolts as recommended and it is Electro-mechanical.
I have the Tractor at idle speed, then pucker up when I engage the PTO. Last time I used it, I had it off the ground, but not too high and it was shockingly quiet and didn't break for several starts and stops. Then I started it again and bang, broke. Sometimes when it starts up it shakes the whole tractor. Dealer said it will not be as bad the more I use it and to keep the pivot point lubed and that initially, because things are so new/tight breaking a few pins is "not unusual"....

 

[DMW]

Check the oil level and condition of the gears of the brush cutter if possible. Grease up the pto shaft, universal joints and the inside of the shaft. As others have said, engage with the least amount of angle on the pto shaft. Something is binding somewhere if the correct grade shear bolt is being used.

 

[Coyote machine]

Any bent/damaged blades or wire bound around anything on the underside of your rig? Can you turn the driveshaft by hand with the PTO shaft disconnected from the tractor PTO stub?

 

[oosik]

I'm sorry but "breaking a few pins is QUITE unusual". Something is not right. The pins simply should not shear on startup. I would press the issue with the dealer.

 

[LouNY]

Without more info it's hard to say,
what type of pto engagement do you have a mechanical lever?
or an electrical switch?
what do you have for a transmission? shuttle ? or hydro?
If its mechanical engaging it slowly and smoothly at the lowest rpm is your answer.
If its electrically activated the first thing is again have the engine rpm at the lowest possible.
If electrical do you have a linked / independent switch? if so try the linked position then
with your foot clutch disengaged, pushed down, turn on the pto switch, it may not run, gently release your foot clutch pedal
and the pto may engage with the main clutch, allowing you to ease it in.

 

[Ritothebull]

I had an old bush hog that came with a tractor I bought and that thing broke a bunch of shear bolts. Everything seemed fine with it mechanically, I tried different grades of bolts and feathered it into gear as gently as I could, sometimes I could cut for hours and other times it would shear off in 5 minutes. I finally sold that thing and bought another mower and now I haven't sheared a bolt in years and I'm using the same tractor so maybe that thing was just jinxed.

 

[WranglerX]

Everything I have seen or read state grade 2 shear bolts...

Dale

 

[DK35vince]

My King Kutter brush hog would sheer bolts at startup also. (PTO turned on by a switch at idle)
I added a slip clutch and haven't had a problem since.