Mowing Shear bolt

jacobsdaddy06 · Apr 29, 2012

Bought a used big bee agri five, hog does anybody know what grade bolt this thing uses, I've tried 2 and it shears on grass, or when I first engage pro (at low rpm) Thanks

kebo · Apr 29, 2012

Generally shear bolts are grade 2, you want them to be the weakest link so they help protect the PTO gears and driveline parts. I don't know that I would advise going to a stronger bolt. Maybe you should try getting a slipclutch and see how that works for you? They cost about a $100 or so.

Jerry/MT · Apr 29, 2012

jacobsdaddy06 said:
Bought a used big bee agri five, hog does anybody know what grade bolt this thing uses, I've tried 2 and it shears on grass, or when I first engage pro (at low rpm) Thanks

They are usually grade 2 bolts. Have you got the correct diameter of bolt?

jacobsdaddy06 · Apr 29, 2012

Yea I have I thought about a slip clutch, yes they are the same size as the one I sheared after I bought it. Grade 2 is what I bought for it, good thing I bought a bag full..

SPYDERLK · Apr 29, 2012

jacobsdaddy06 said:
Yea I have I thought about a slip clutch, yes they are the same size as the one I sheared after I bought it. Grade 2 is what I bought for it, good thing I bought a bag full..

Does the collar fit the shaft well? If so, and youre shearing as easily as you say, its likely that the shear is made for Gr5. Grade 5 shears at a higher level, but shears more cleanly tha Gr2 which is kinda gummy by camparison. Never go above Gr5 because Gr8 will damage shaft and collar.
larry

Mark Page · Apr 29, 2012

A slip clutch is the way to go. Swapping out shear bolts is a pia.
How about a grade 5 in a smaller diameter?

daveinnh · May 11, 2012

You should ask big bee agri five about the correct shear bolt size.

I bought a Salsco chipper, made in CT, and replaced with an Imperial dia shear bolt. I felt a little play and several sheared in low-load conditions.

After calling Salsco, they advised me that the shear bolt should be metric - i.e. made in US for both American and other export markets; other markets don't have imperial bolt sizes readily available.

Works fine since.

zkurtb · May 14, 2012

If you have - or can find a copy of - the manual, it should specify. My Deere brush hog uses a grade 5 - which I bought used and had to get help from fellow TBNers and other internet searching to figure it out. The dealer tried to tell me grade 8(!). Glad I didn't listen. So you can ask the dealer, but also use common sense, they may be well intentioned but off the mark...

Tractor Seabee · May 14, 2012

Land Pride shear bolts are grade 3 and they recommend using grade 5 if it shears too often. They caution against grade 8. I have a clutch on my RT and am about ready to junk it and replace w/ a shear pin. I have to disassemble the clutch twice a year, clean it up, and reinstall. Takes an hour of cussing to get it done. A little rust on the plates (it rains a lot here) and they do not slip anymore. I have a lot of big rocks in the garden spot. Hopefully I am getting them all dug out. I carry a 3' crowbar to work them out. My LP hog has a shear bolt and never sheared last year.

Ron