Bush hog busted?

[stormpetrel]

Howdy everyone!! It's been a long winter......my tractor was down with the 4wd gearbox bearings needing replacement. I finally got it back together, and have been working the tractor like crazy this past week; I have cleared brush and trees that haven't seen daylight in decades, got stone walls cleared, and in general had a great time improving our place.

This morning I hit a rock while backing the bush hog into very thick brush. The pto shaft is turning, but the blades are not. Is there something in the gearbox that shears off to prevent damage, that I must now replace? Or is it worse than that?

 

[grainger12002]

should be a pin(bolt)where the pto shaft meets the gear box on the mower, it might look like its still there but you will probably find its only half there......

 

[stormpetrel]

should be a pin(bolt)where the pto shaft meets the gear box on the mower, it might look like its still there but you will probably find its only half there......

Thanks.......that's what I was hoping!! Where do you get a new one?

I see we're almost neighbors.......

 

[Ginormous]

You should be able to buy a new shear pin at TSC or other farm supply type places. Of course, you need to figure out the size. If you happen to have a manual for the bushhog, that gets really easy. :thumbsup:

 

[stormpetrel]

Thanks folks.....I'm very relieved. I guess I hit one too many rocks.......

 

[grainger12002]

is that what you found ? If so you can use a hardended bolt,check the size as stated and start the mower off easy so it doenst break again....

Yes, we are close, i was born in RI at Kent County hosp....

 

[284 International]

...If so you can use a hardended bolt...

I know some people do this, but it seems like borrowing trouble to me. It's a nuisance to replace a shear bolt, but the shear bolt is also protecting the tractor and the mower from some of the horrific impact forces when the blades bang into rocks. As tough as a shear bolt can be to replace, I'd rather mess with one of those than the innards of the tractor.

I don't know for sure that is the choice: Hardened bolt vs PTO components of the tractor, but if the bashing is sufficient to shear the bolt off, it has to be rattling the tractor's powertrain, too. I'd rather err on the easier side than the more abusive side.

 

[4520RX]

I use a grade 2 bolt with a nylock that is what the manufacturer recommended but my hog is only rated to 60 hp

 

[stormpetrel]

I know some people do this, but it seems like borrowing trouble to me. It's a nuisance to replace a shear bolt, but the shear bolt is also protecting the tractor and the mower from some of the horrific impact forces when the blades bang into rocks. As tough as a shear bolt can be to replace, I'd rather mess with one of those than the innards of the tractor.

I don't know for sure that is the choice: Hardened bolt vs PTO components of the tractor, but if the bashing is sufficient to shear the bolt off, it has to be rattling the tractor's powertrain, too. I'd rather err on the easier side than the more abusive side.

Funny you should mention bolts, cause that's exactly what was on there!! I have used the tractor for bushogging 4+ acres.......HARD for over a full season. When I knocked the remains of the "pin" out, I noticed the end of a bolt on the deck, freshly sheared,and it fit perfectly with the other half.

I guess the guy I bought it from had a steak of Swamp Yankee in him. Certainly, as someone who lives on a little island with no Tractor Supply store, you can bet I found another hardened bolt and put 'er right back in!!

We'll see how she works....I expect it'll do fine, the other one seemed to. I guess a bolt is just weak enough to be able to shear off before any damage is done to the gearbox on the deck or the powertrain.......

 

[stormpetrel]

I use a grade 2 bolt with a nylock that is what the manufacturer recommended but my hog is only rated to 60 hp

Mine's a 5', on a 22 hp PTO output tractor. I doubt it's even rated for 60 hp....

 

[clemsonfor]

There was a "bolt" in it cause thats waht a "shear pin" IS. For your size tractor you need to use a grade 2 bolt. If it was a bigger tractor you can use a grade 5 but DO NOT use a 5 in your tracotor. Other wise next time you may be writing about how to replace busted PTO gears or what to do about a busted gear in your bush hog. Go get a hand full of bolts and nuts and keep them on your tractor so that if it happens again you just punch the old half out and put a new on in there.

 

[Bartcephus]

Most of the time a grade 2 bolt is what is specified. A hardened bolt may damage the shaft more than the specified grade 2 bolt, and/or likely shears at a higher torque on the PTO. I'd go with the softer grade 2 if it were me.

 

[stoatspur]

Please don't use a "hardened" bolt. That would be a grade 5 or 8 and neither is good as shear protection. 4520RX is right. So is BARTCEPHUS. If you are going to use a hardware store bolt, make sure it is a grade 2. Grade 2 is soft enough to provide shear protection. 5 or 8 may/will not shear, thus not protecting your equipment.

 

[clemsonfor]

most say only to use a grade 5 bolt in a larger say 55+ hp tractor as their gears are tougher to take the HP. BUT the bush hog may not be? Like i and others said take that 5 outta there, it would be fine if in an area known to be rock free to get you through a day but you NEED to put a grade 2 bolt in there.

 

[Ginormous]

... unless you're looking for a good excuse to buy a new tractor.

 

[clemsonfor]

Or if your lucky a new gearbox for your bush hog.

 

[stormpetrel]

Ok, I'll put a #2 bolt in. But......won't a hardened bolt shear quicker, due to being more brittle? Any metallurgists out there that can answer this?

 

[clemsonfor]

Ok, I'll put a #2 bolt in. But......won't a hardened bolt shear quicker, due to being more brittle? Any metallurgists out there that can answer this?

NO it will shear at a higher PSI due to having a HIGHER shear strength!! higher grades are stronger in shear strength and tensile strength. I promise. My bush hog (Jbar brand) manual says to use "grade 2" bolts i think its 3/8 size? if you dont trust us that much i can copy it if i ever find it but you can just look up Bush hog brand online, they post all their manuals, and you can look it up, or look at king kutter they all take bolts, grade 2!!

 

[stormpetrel]

NO it will shear at a higher PSI due to having a HIGHER shear strength!! higher grades are stronger in shear strength and tensile strength. I promise. My bush hog (Jbar brand) manual says to use "grade 2" bolts i think its 3/8 size? if you dont trust us that much i can copy it if i ever find it but you can just look up Bush hog brand online, they post all their manuals, and you can look it up, or look at king kutter they all take bolts, grade 2!!

It's not that I don't trust anyone,it's just a question based on my own experience with softer metals that bend and don't break, where harder metals crystallize/snap real easy because harder metal usually = more brittle metal. Just curious. You did see where I wrote I would put a grade 2 bolt in, right?

 

[kenmac]

I have sheared many bolts. I use the cheap bolts from Lowe's / hd. I have several spares on hand.

Haven't seen you around in a while
By the way Grapple is working GREAT !