Snowblower kubota b2782 shearing inner auger pins
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kthompson
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jim1890 welcome to TBN. Maybe it is my ignorance but think you need more info here on what type of auger and the use of it. Are you sure they used a grade 8 bolt for a shear bolt? But my thought if doubt you would see much improvement in preventing shearing with this change. Maybe you could find chart on shearing factor for different size and grade bolts. Have you figured out what is causing it to shear other than possibly sloppy hole? Is it only hitting on one side and both sides not sharing the shearing effect?
Dave M7040
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The shear bolt question is a critical one on the style of blower you have with the gear box in the middle of the auger.
Which shear bolt(s) are failing. Only the inner auger ones as you mention?
What is the design where your fan shear bolts go. There were changes after lots of problems.
This image is of the latest design.
This image is the design of fan shear bolt with problems
At one point Kubota was supplying shear bolts with two grooves cut in them to make shearing them easier.
Owners who got too adventurous ended up with this.
Welding and re drilling the holes has been the most successful fix or if you can, drill a new hole.
Post some photos.
Dave M7040
Langanobob
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The shear bolt in question on my blower is just a regular grade 8 bolt, no grooves in it. It occurred to me that if you are buying auto parts store grade 8 bolts, the threads shouldn't go the full length of the bolt. The shank of the bolt that actually gets sheared should not be threaded. If you're using bolts that are threaded all the way to the bolt head, the effective bolt diameter is quite a bit less than 1/4" and the bolt will be weaker. Not likely that's your problem but I thought I'd pass it on for what it might be worth.
Is it shearing without a visible cause, like rocks jamming the works or going to fast into heavy packed snow? It does sound like you need to repair the wallered out holes. Unless you get some valid engineering data on it, I'd also be real cautious about experimenting with a larger diameter bolt, even if it's a grade 2. Not sure if there are any real spec's for a grade 2 bolt. Good luck with it, I know how frustrating some of these problems can be, especially when it's cold and snowy.
Is it shearing without a visible cause, like rocks jamming the works or going to fast into heavy packed snow? It does sound like you need to repair the wallered out holes. Unless you get some valid engineering data on it, I'd also be real cautious about experimenting with a larger diameter bolt, even if it's a grade 2. Not sure if there are any real spec's for a grade 2 bolt. Good luck with it, I know how frustrating some of these problems can be, especially when it's cold and snowy.
dragoneggs
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Don't mean to derail this thread right off the bat, but in your first pic, are those OEM bolts? Why is there 6+ threads protruding? Something doesn't look right to me.The shear bolt question is a critical one on the style of blower you have with the gear box in the middle of the auger.
Which shear bolt(s) are failing. Only the inner auger ones as you mention?
What is the design where your fan shear bolts go. There were changes after lots of problems.
This image is of the latest design.
This image is the design of fan shear bolt with problems
At one point Kubota was supplying shear bolts with two grooves cut in them to make shearing them easier.
Owners who got too adventurous ended up with this.
Welding and re drilling the holes has been the most successful fix or if you can, drill a new hole.
Post some photos.
Dave M7040
Dave M7040
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First I do not have one of these blowers but a few years ago did a lot of research for owners who did and were plagued by problems.
The pictures are of OEM bolts provided by Kubota dealers to various owners.
Somewhere I might still have pictures of these shear bolts still in a Kubota sealed bag.
There were also bolts with one groove cut in it instead of two.
The big product change and major improvement was when the fan shear bolt incorporated a flange instead of a bolt through the shaft and fan hub.
Kubota does NOT manufacturer blowers.
Kubota buys blowers made by RAD in Quebec Canada for Kubota and other tractor manufacturers.
The color changes, Kubota orange, John Deere yellow, etc
RAD does not deal with consumers as their customers are the manufacturers of the tractors.
EN - RAD Technologies Inc. – RAD Technologies Inc.
Dave M7040
Hello Dave and thank you for your info I took some pics didn't know how to post them. Went to a faster store and got some 1/4x11/4 grade 8 bolts with a shank not full threads. I cleaned everything and put it back together going to try next snow
.
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