# Are there specifications for installing shear bolts?



## chrisexv6 (Feb 4, 2014)

Did some mid-season maintenance on my 2006 Ariens 926LE last night. Turns out one of the shear bolts was BENT but not sheared (it snapped when I was trying to remove it to grease the auger shafts)

Even worse was the fact that it bent NOT at the groove machined into the bolt itself....it bent somewhere in the threaded area. Now, this shear bolt was purchased from an Ariens dealer but isnt genuine Ariens (Stens replacement part, correct part number as I cross referenced it before installation)

So either the bolt was wrong or I installed it wrong. Which lead me to the manual, where I couldnt find a thing about how to correctly install them. 

Do they need to be tight? Loose? Is there a specified torque for the nut?

Other than relying on the part number, is there a way to verify its the correct part (i.e. where should the machined groove be in relation to the outer diameter of the auger shaft?)

Thanks in advance.

-Chris


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## UNDERTAKER (Dec 30, 2013)

some one might have got cute and stuck a grade 2 bolt in there. just tighten down until snug on those bolts.


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## chrisexv6 (Feb 4, 2014)

POWERSHIFT93 said:


> some one might have got cute and stuck a grade 2 bolt in there. just tighten down until snug on those bolts.


Only if the dealer sold me the wrong part.....I installed it myself the last time it broke. The fact that it had the machined groove made me figure they werent the wrong part.

Ive since bought a pack of 10 bolts from Ebay that WERE the Stens part (Stens bag, etc) so we'll see how that works instead.


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## sr71 (Mar 25, 2013)

Mid season maintenance - kudos to you. I've got a heated shop and the blower never gets mid season maintenance….(end of season/beginning for me). 

the failure (bending) sounds like a "grade 2 like" bolt - softer …tends to bend and when they shear they don't shear clean…hard to describe but kinda mushroom which makes it sometimes problematic to remove. 

anyway…I'm not aware of any specific shear bolt install procedure ….. the groove indicates a shear bolt so perhaps not heat treated properly …..cheap alloy - who knows. I will add however that over torquing can stretch the bolt ….which can lead to premature or easier failure. I just snug the nut.


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## liftoff1967 (Jan 15, 2014)

Interesting. 

This fall when I did my maintenance on my 2014 deluxe 30, I had a swapped out a bent shear bolt as well. Said shear bolt was right from the factory.


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## Shryp (Jan 1, 2011)

I have pulled bent ones out of Ariens as well.


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## UNDERTAKER (Dec 30, 2013)

Another mystery is taking shape here on the forms.


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## grouchy-hermit (Feb 5, 2015)

Is it posssible that just the bolt hit something instead of the auger? Maybe just a glancing blow that wasn't enough to finish it off?


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## chrisexv6 (Feb 4, 2014)

I cant be 100% sure but I think what did it was clipping the belgian blocks that we have concreted in as a border around our driveway. I always try to creep up close to them without the drive engaged (just pushing the blower) so as to avoid really hammering into them, but one time I got a little too close with the drive engaged.

The auger just barely clipped it and lifted the bucket off the ground, I pulled back right away and no harm after that.

Maybe it was enough to bend the bolt but not break it?

Should the groove in the shear bolt line up with the outer diameter of the auger shaft? Im wondering if they are the wrong bolts for the application regardless of the material grade.


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## sscotsman (Dec 8, 2010)

Im not sure a bent shear bolt is all that mysterious..
there are two ways to look at it:

1. A bent shear bolt could mean its not a "proper" shear bolt, its *stonger* than it should be, and instead of breaking, it bent without breaking, and that is bad.

or.

2. Do all "proper" shear bolts bend a little *before* they break? im not sure..
(in six years of owning a snowblower, I have not broken one)
but if they do bend a bit *then* break during the normal course of their shearing duties, could it be possible that a bent shear bolt could be a "good" shear bolt that simply didnt quite get enough pressure to break completely? only enough to bend?

I have no idea if that theory is correct or not..but its a thought that came to me.

Scot


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## Sid (Jan 31, 2014)

If the auger shaft is 1" the grooves should be 1" apart the same for 3/4" shafts 3/4" apart, of course you have to know your shaft diameter. On some units with 3/4" shafts, they just use full threaded 1/4" bolts, but they must be full threaded. The auger holes on one of my Sears/Murray augers are egged, because I had to put in a regular bolt in an emergency. Thats a summer time repair job that never happened.
Sid


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## mml4 (Feb 19, 2015)

I have a TroyBilt 824 from before the MTD takeover. It was built by Bolens/GardenWay. The service manual calls for 11 foot pounds of torque when tightening the shear bolts. The oem bolts are the type that have a smooth shoulder with the threaded portion completely protruding from the auger.
It is the only machine/manual that I have heard of quoting a torque setting for shear bolts.
Marc


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