Snow Shear bolts in 47" front snowblower

[chipsndust]

I have been using grade 5 bolts for shear bolts in the augers and impeller (1 X 1/4-20 , with nylon insert nuts). They seem to be breaking pretty easy.

I am tempted to try grade 8 bolts of the same size, sure seems like a grade 8 1/4" bolt would break before anything else in the drive train?

I stopped buying the shear bolts from the dealer at about $4.00 each.

Anyone using grade 8 bolts for shear bolts?

 

[BleedingOrange]

I have the same blower, and would not upgrade to grade 8 bolts. They original shear bolts are made to shear, if the blower gets jammed, before you damage a gearbox. I,m sure you can probably get cheaper bolts at TSC, or a hardware store.
It,s much cheaper to replace a few shear bolts a year, than a gear box, or worse.

 

[bigtiller]

I would stay with the grade 5 bolt, but there is no reason to pay that much for them. You should be able to buy them by the pound at any box store for a whole lot less. A trick I learned is when replacing a shear bolt, make sure it is clean and dry, then use some blue thread lock-tight. I think the nylon lock nuts work loose and things start moving a bit and that is what breaks the bolt. Or try using the more expensive conical lock nut.

 

[Henri88]

Bigtiller is right! I use to break shear bolts like crazy the first year I had it, until I realize that the bolt were coming loose. I did not use lock-tight, but I did put them tighter. Fix my problem. Now I brake one maybe two per winter. Didn't brake any this winter, yet.

 

[chipsndust]

Thanks, guys.

I have been buying the grade 5 bolts at TSC.

I have noticed that they tend to loosen up. I'll keep a closer eye on the tightness and maybe try a different type of locknut.

 

[etcallhome]

Agree with the others ,the nuts work loose and that is when the bolts seem to break . I don't like using the nylon because they seem to work loose .
Last few times I tighten the bolt and nut and then put another nut on and tighten it, I went and was able to do the 9 driveways 3 times before breaking a bolt..

 

[Avondale]

I have a rear blower but was going through many shear bolts, (TSC 1/4"x20 plated Gr 5), mainly on the fan side but sometimes on auger, even on flat, smooth driveways. I found that when I "opened" up the chute lid to blow farther, I broke much less of the fan bolts then when I had the chute "down", which reduced flow and trajectory. The auger seems to be able to shove more snow than the fan could eject. When wide open, rarely break a bolt and then mainly the auger after hitting something (like my dog's XL KONG toy with Nylon rope).