Gotta be an easier way to learn ...

[bky]

well i can tell you from experance thet you have to use a grade 2 bolt for shear bolts on bush cutter because if not you will and i asy you will break a pto shaft inside of the tractor.
i know from experance.
i sheard my bolt in cutter well i went to the barn and grab sam dia bolt and back to cuttin the band hit a rock and found that i broke pto shaft inside the tractor .
now fixin it wasnt a lot of fun . live and learn i guess

 

[duanet]

I haven't broken a shear pin (bolt) yet on my 20 year old CT brush cutter yet, but I did get into a strange problem earlier this week. I haven't used it much on my 4100 (did a lot on my old 2N), and as I lowered the deck over a slight bank (maybe not so slight), the PTO shaft telescoping shields extended fully and came apart without my noticing it. I tried to raise the 3PH back up and really jammed the shield ends together. Nedless to say, there was no way to get them to slide and no way to get the PTO off the tractor. I had to go get my car ramps, run the back of the tractor up on those and extend the top link to lower the brush cutter enough to remove the PTO shaft from the tractor. Once that was done, I could bring things back to the shop and beat the shields back in shape so they would slide once again.

Like you said, live and learn. Next time I'll set my depth control stop at a safe position.

<font color=green>Duane</font color=green>

 

[Harv]

<font color=blue>I don't remember which one you have.</font color=blue>

Neither do I, Bird.

The darn thing is sitting just a few feet from my tractor, but I'm 120 miles from both of them.

It's a fairly high-end model, 6.5hp (I think) with electric start. I've attached a bad picture just in case you can tell if it's similar to yours. You're right, mine can also be started with the pull rope, and it stops when you pull the throttle lever all the way back.

I'll have to take a look at the wiring and cabling to see what you're talking about. Remind me next time I'm up there, okay? /w3tcompact/icons/grin.gif

 

[Bird]

Harv, that looks like the same machine as I have, although it probably won't make any difference. Regardless of which one you have, it will undoubtedly have a number of wires with a connecting plug that can get dirty and lose contact. I'd consider it a bit unusual, but certainly not unheard of and I should have thought of that right off myself. Mine is the 6hp overhead valve Briggs and will be 4 years old in a couple of months.

 

[jasonf]

I know the feeling. I went down to the neighbors and saw then with a shovel (hee hee hee). So I proudly motion them away with my hand and put the front mounted snowblower into action. I get about 20 feet into it and the blower stops. I limp home and then check what happened. Sure enough a 2X4 was left in the drive way and it broke the blower shear bolt in a hurry. Now when I go to 'help' out the neighbors, I ALWAYS ask is there anything in the driveway that will clog the blower?

P.S. The manufacture's shear bolts are usually pretty expensive. I now make my own on the lathe. I take grade 2 bolts and machine the grooves into them. I can by a whole box of 5/16 X 2 1/2 for about $2 a box at the supply house. Put a couple grooves in each and I'm in business. This could also be done by chucking the bolt into a drill and then spinning it with a file up against it to make the grooves. By the way I have learned over the years that if you look at the head of a bolt and add 2 to the number of 'hash marks' you get the grade of the bolt. If there are no marks on the head then the rule still applies, 0 hash + 2 = grade 2 bolt. It sounds like you had a grade 5 bolt, I have tried using the grade 2 so that there is not so much torque transmitted to the PTO. If you constantly break the grade 2's then you could go back up to a 5. I find that the 2 work very well and are available at Lowes Home Depo Etc.... If you don't machine the grooves into the bolts I find that you have to really hammer then out. With the grooves they come right out with a tap. Jason

 

[DVerbarg]

Jason,

The shear pins for my PTO shaft are not proprietary, just 5/16 x 1" bolts with std nuts. This made it very cheap and easy to replace, just $1.21 for 12 bolts (you can never have enough, right?!) /w3tcompact/icons/smile.gif

I used the grade 5 since that is what the OEM had on it. On a rotary cutter I have changed pin grade down to grade 2 (from 5) and was shearing pins left and right (thought I would save a little aggravation by not having to drive as far to get the grade 5). That was dumb. /w3tcompact/icons/blush.gif

 

[markcg2000]

Don't feel bad... I went through almost the same thing /w3tcompact/icons/laugh.gif. Anyhow, attached shows where mine is... and sounds like yours is there, too.

 

[EdKing]

I remember when I got my rotary mower. Sheared 2 bolts figuring out the hieght and leveling, then hit a hidden fence post and busted number 3.

Ed King

 

[TerryinMD]

Haven't had a shear bolt go yet, but if you have any equipment with a slip clutch and it is prompted to do its job - you're in for a treat.

I have a rotary tiller with a slip clutch and DaveV's original post reminds me of my <A target="_blank" HREF=http://www.tractorbynet.com/cgi-bin/compact/showthreaded.pl?Cat=&Board=implement&Number=72640&Search=true&Forum=All_Forums&Words=roto&Match=Entire%20Phrase&Searchpage=3&Limit=50&Old=6months&Main=72640>encounter</A> with the slip clutch and my rotary tiller./w3tcompact/icons/crazy.gif/w3tcompact/icons/grin.gif/w3tcompact/icons/eyes.gif/w3tcompact/icons/blush.gif/w3tcompact/icons/laugh.gif

Terry

 

[frank_f15]

DAVE: glad u figured it out at no cost/w3tcompact/icons/cool.giflook at it this way, u learned something, did not cost you $$$$$$ and sometime soon someone else is going to have the same problem and remember that they read about it on tbn, and they will be most gateful to u./w3tcompact/icons/love.gif experience is the best teacher.