B2782 shear bolts

[TBayOrange]

Had the guy at the parts counter at my local Kubota dealer tell me I could use just a regular grade 5 stainless bolt for my shear bolt, is anybody doing this or tried it?

Cheers

 

[KeithG]

I tried grade 5 in mine and it seemed to sheer a lot more often than the grade 8 bolt. Pain in the neck to change them multiple times during a storm...

 

[TBayOrange]

I tried grade 5 in mine and it seemed to sheer a lot more often than the grade 8 bolt. Pain in the neck to change them multiple times during a storm...

That's interesting because the shear bolts that you buy from them at the parts counter are grade 5 that have been weakened. I would be grade 8 bolts would be to strong and end up causing damage.

Cheers.

 

[07wingnut]

If it is anything like the b2750 snowblower, it takes grade 5 on the augers and grade 8 on the fan. Both these bolts have been degraded by grooving at the shear locations.

 

[200mph]

Had the guy at the parts counter at my local Kubota dealer tell me I could use just a regular grade 5 stainless bolt for my shear bolt, is anybody doing this or tried it?

Cheers

You need to be specific on which shear bolt you're referring too. There is one for the auger and a different one for the fan.

The auger bolts have a cut detail to reduce the shank diameter. The fan looks to use a standard uncut/unmodified bolt.

You can see pictures of both at the following link, plus the description.

You might be hard press to find a Stainless Steel Grade 5 bolt. I typically lube the shear bolts with moly grease to prevent them from rusting in place. (please note the fan is grade 8)

Referencing other snowblower models is irrelevant and only leads to confusion as their is a plethora of different types.

https://messicks.com/ku/86613 Once page load type SHEAR in the search box. Two items will come up. There are pictures of each if you select the camera icon.

15 BOLT, SHEAR 51&6- Shear bolts 70060-01337 $2.86 2 5/16(SPECIAL) LOCKWASHER & NUT 657296

20 SHEAR BOLT/GR 8- SHEAR BOLT 70060-01074 $1.26 1 1/4 NC*1 1/4 GRADE 8 & STOVER NUT 656048

Notice the fan shear bolt is grade 8.

Hope this helps

 

[TBayOrange]

You need to be specific on which shear bolt you're referring too. There is one for the auger and a different one for the fan.

The auger bolts have a cut detail to reduce the shank diameter. The fan looks to use a standard uncut/unmodified bolt.

You can see pictures of both at the following link, plus the description.

You might be hard press to find a Stainless Steel Grade 5 bolt. I typically lube the shear bolts with moly grease to prevent them from rusting in place. (please note the fan is grade 8)

Referencing other snowblower models is irrelevant and only leads to confusion as their is a plethora of different types.

https://messicks.com/ku/86613 Once page load type SHEAR in the search box. Two items will come up. There are pictures of each if you select the camera icon.

15 BOLT, SHEAR 51&6- Shear bolts 70060-01337 $2.86 2 5/16(SPECIAL) LOCKWASHER & NUT 657296

20 SHEAR BOLT/GR 8- SHEAR BOLT 70060-01074 $1.26 1 1/4 NC*1 1/4 GRADE 8 & STOVER NUT 656048

Notice the fan shear bolt is grade 8.

Hope this helps

The shear bolts i got from my local parts counter were all grade 5, and in fact the guy went so far as to say I could use the auger bolt in the fan.

The auger bolts I was sold were all machined to reduce the diameter, the fan bolts were not machined, but all were grade 5 stainless.

I work maintenance at a paper mill so I can get grade 5 stainless by the thousands.

Cheers

 

[RCW]

These are for the BX2750D blower.
1 grade 8 for impeller, 2- grade 5’s for augers. Show machined grooves.
Guessing similar.
Given the very high cost of blower replacement parts like gearbox, shafts, bearings, etc. I decided I would stick with OEM shears.
Guessing I break 3 a year average, so $25 worth of them lasts a couple/few years.....

Sent from my iPhone using Tapatalk

 

[07wingnut]

We just went thru a dump of 2 feet of heavy wet snow. It took 12 shear pins for the fan and 5 hours to clear up the mess here and at my neighbor. It didn't seem to make much difference taking the full cut very slowly, or taking smaller cuts. Eventually, the augers would slowly load up, and the fan shear pin would go. Interestingly, the auger shear bolts never went and the chute never plugged even once.
As RCW states, the cost of the pins is cheap, compared to the cost of replacing blower parts. To lessen the stress to my wallet, I buy grade 5 and grade 8 bolts and groove them myself. If the thread on the bolt happens to fall where one of the grooves should be, then you only need to groove the smooth shank.
Using correctly grooved shear bolts has another benefit, other than protecting the more pricey bits. They shear clean, and the sheared leftovers are usually gone. If the shank is still in the shaft, it is easily removed.

 

[RCW]

Yeah wingnut, I average 3 a year but can go through a bunch in a hurry.
I seldom break impeller pins. Seems to be auger more often.
We had 3 feet couple years ago. Did mine and 4 neighbors twice.... no pins broken....go figure.


Sent from my iPhone using Tapatalk

 

[Fatfenders]

The replacement shear bolts given to me by the dealer when my snowblower was delivered were not grooved. Looking up the part number for the auger and fan shear bolts for my LX2980 which were found on Messicks' site are not grooved either.

Head markings (there are none) on my auger bolt identify it as a Grade 2 and the fan (3 lines radiating), Grade 5.

These are the Auger shear bolts for my application:
https://www.messicks.com/part/77700-04339/bolt-shear-1-4

And the fan shear bolts:
https://www.messicks.com/part/70060-04440/shear-bolt5-16-n

Hopefully that helps?

 

[BAP]

The replacement shear bolts given to me by the dealer when my snowblower was delivered were not grooved. Looking up the part number for the auger and fan shear bolts for my LX2980 which were found on Messicks' site are not grooved either.

Head markings (there are none) on my auger bolt identify it as a Grade 2 and the fan (3 lines radiating), Grade 5.

These are the Auger shear bolts for my application:
https://www.messicks.com/part/77700-04339/bolt-shear-1-4

And the fan shear bolts:
https://www.messicks.com/part/70060-04440/shear-bolt5-16-n

Hopefully that helps?

That’s a different model snowblower than the one originally in this thread. So they may have changed the shearbolt design.

 

[KeithG]

A long time ago I posted information about shear bolts because I thought a Grade 8 bolt was too strong for the impeller fan on my snow blower. Rather than repost the entire post here is a link (that I hope works) to the original post:

Everything you need to know about SHEAR BOLTS

I know this is a long post but I am a believer in not trusting anyone because they posted something on the internet. So I am providing all details and references so you don't have to believe me you can see how the figures were calculated. If you don't want to read what led to discover the...

www.orangetractortalks.com

One thing I found out is that Grade 8 bolt is threaded which reduces the force needed to shear the bolt.

Second thing I found out last winter is if you tighten the bolt too much on the fan it won't shear. I found this out because a piece of my tar driveway when through the snowblower and ended up on my lawn. During the winter I noticed a slit in the bottom of the fan housing. I am guessing that piece of tar did that, so I am going to undo the shear bolt and make sure the two flanges did not rust together from the bolt being too tight.

Hope this helps... -Keith

 

[07wingnut]

In reference to post #8 about going thru a handful of shear bolts, the problem was not the heavy snow. What was causing the fan bolt to shear, was vibration fatigue, brought on by the drive reduction sprockets running with a chain that was stretched just a tad too much. New chain, no more shear bolt problems.

 

[Fatfenders]

That’s a different model snowblower than the one originally in this thread. So they may have changed the shearbolt design.

Can't disagree with your there. If Kubota changed shearbolt design, it would stand to reason the new design, if indeed there is one, would suffice just fine for the OP's blower. Per Messicks site, it shows 3 different 5/16" shear bolts fitting the OP's blower,. One of the 3 shear bolts is grooved. Go figure.
https://www.messicks.com/wiki/kubota/b2781b-b2782b

For my blower specifically, Messicks Kubota wants $1.72/ ea for the 1/4-20 auger bolts and $1.60/ea for the 5/16 -18 fan bolts.

I went to Fleet Farm and bought bulk 1/4-20, Grade 2, fully threaded bolts and nylock nuts for the auger that cost 2.89/lb and bulk 5/16 - 18, Grade 5 bolts and nylock nuts for the fan that cost $3.19/lb. So, for the price of the 2 "Kubota Bolts" in one size, I got a bag full.

All I'm offering is, save some money and buy bulk. Just make sure they are the recommended Grade for the blower one owns. I love keeping money in my pocket if possible...

 

[BAP]

Can't disagree with your there. If Kubota changed shearbolt design, it would stand to reason the new design, if indeed there is one, would suffice just fine for the OP's blower. Per Messicks site, it shows 3 different 5/16" shear bolts fitting the OP's blower,. One of the 3 shear bolts is grooved. Go figure.
https://www.messicks.com/wiki/kubota/b2781b-b2782b

For my blower specifically, Messicks Kubota wants $1.72/ ea for the 1/4-20 auger bolts and $1.60/ea for the 5/16 -18 fan bolts.

I went to Fleet Farm and bought bulk 1/4-20, Grade 2, fully threaded bolts and nylock nuts for the auger that cost 2.89/lb and bulk 5/16 - 18, Grade 5 bolts and nylock nuts for the fan that cost $3.19/lb. So, for the price of the 2 "Kubota Bolts" in one size, I got a bag full.

All I'm offering is, save some money and buy bulk. Just make sure they are the recommended Grade for the blower one owns. I love keeping money in my pocket if possible...

Yes, but are your bulk bolts grooved like the OEM bolts are to make them shear properly without damaging the rest of the drive line?

 

[Fatfenders]

Yes, but are your bulk bolts grooved like the OEM bolts are to make them shear properly without damaging the rest of the drive line?

My original bolts are not grooved on my LX2980 and as I said, 2/3 of those shown for the OP's blower are NOT grooved. The replacements available from Kubota for my blower are not grooved at all.

That is my point. It would appear Kubota has decided the grooved bolts, at least for the commercial blower are not needed. The threaded portion in shear, will snap just as fast as one that is grooved, maybe faster as the weakened area is spread over a larger area.

 

[Orange1forme]

Bringing this up again because my local Kubota dealer is out and no ETA on new stock.

When I look at the bolts for the fan, compared to my auger bolts, these do NOT have a relief groove and to me appear to be just a standard bolt.

What is your opinion on the bolt, specialty shear or just standard.

No need to rehash the "only by Kubota shear bolts" portion unless someone has tried and failed with the standard bolts.

Thanks!!!

 

[DustyRusty]

If you have one of the original shear bolts, take it to your local lawn mower shop and see if they have any like your Kubota Shear bolts. Also, some hardware stores have shear bolt selections. I just looked at Messicks website, and they have over 100 in inventory according to the website. Part # 70060-01338 Price $3.23 . I think that I will be purchasing some soft bolts and grooving them myself when I run out.

 

[Orange1forme]

If you have one of the original shear bolts, take it to your local lawn mower shop and see if they have any like your Kubota Shear bolts. Also, some hardware stores have shear bolt selections. I just looked at Messicks website, and they have over 100 in inventory according to the website. Part # 70060-01338 Price $3.23 . I think that I will be purchasing some soft bolts and grooving them myself when I run out.

I am NOT buying from Messick's, the shipping is outrageous on something like this!!!!!!!

Again, no groove on these.

 

[BAP]

Bringing this up again because my local Kubota dealer is out and no ETA on new stock.

When I look at these, compared to my auger bolts, these do NOT have a relief groove and to me appear to be just a standard bolt.

What is your opinion on the bolt, specialty shear or just standard.

No need to rehash the "only by Kubota shear bolts" portion unless someone has tried and failed with the standard bolts.

Thanks!!!

Bringing this up again because my local Kubota dealer is out and no ETA on new stock.

When I look at these, compared to my auger bolts, these do NOT have a relief groove and to me appear to be just a standard bolt.

What is your opinion on the bolt, specialty shear or just standard.

No need to rehash the "only by Kubota shear bolts" portion unless someone has tried and failed with the standard bolts.

Thanks!!!

Are these the Fan shear bolt or are you using this in the auger?