Shear Bolt Price Explosion!!

[torch]

Easy to make your own
1. determine 'strength' of bolt. No marks on head= Grade 2, 3 dots or lines = Grade 5

I'm not sure that's true of even plated grooved shear bolts. It's certainly not universal of stainless steel bolts. And it's completely wrong if the bolt is metric.

The groove is more than "slight" -- in my experience they are close to the full thread depth. IE a 5/16" shear bolt will be closer to 1/4" diameter at the groove.

 

[GreensvilleJay]

As for Metric, convert to whatever markings are equal to Imperial grade.Chart is in every Kubota Owners manual, somewhere.

Have never seen SS shear bolts,plating doesn't change strength of bolts, it for 'corrosion resistance'.

I said 'slight' cause you don't want to go deeper than the official real shear bolt depth, If you go deeper, it'll fail before it should, go shallow and it won't break as easily.

I've used Grade 5 5/16" bolts, NO groove, on my rototiller for 8-10 years.They break fine when rock gets stuck between the frame and blades. Use Grade 2, 1/4-20 bolts, no groove for the riding and walkbehind snowblowers.Try to chew a skid buried in the snow, they fail.

 

[BAP]

This thread is as good as the filter and oil threads. Spend $40-80k on a tractor and implements, then beech about $5 parts and wonder why you have a$5k repair bill because you used the $1.50 off brand part instead. Popcorn and Beer time.

 

[hagrid]

Tariffs, not Kubota.

'Rona.

Also, the heebie-jeebies.

 

[nbryan]

I have purchased these aftermarket shear bolts in the past, and I'll bet that if I combined the handful of bolts I purchased from the Kubota dealer before the price increase with the ones I purchase on eBay, you would be hard-pressed to find any difference.
Yes, I know exactly what a gearbox costs, and what has to be done to replace it. When was the last time that you changed the gear oil in your gearbox? If you are like the majority of snow blower owners, the answer will be NEVER!

Twice I've changed my blower's gear box oil. I also don't mess around with maintenance.

I don't need to "hard press" myself at all. I get the dealership parts. Done.

 

[torch]

I've used Grade 5 5/16" bolts, NO groove, on my rototiller for 8-10 years.They break fine when rock gets stuck between the frame and blades. Use Grade 2, 1/4-20 bolts, no groove for the riding and walkbehind snowblowers.Try to chew a skid buried in the snow, they fail.

Hey, your machine, your choice.

For a plain single shear plane style the manufacturer often specs a plain bolt. Kubota specifies a 1/4-20 Gr. 2 bolt for my auger and a 6mm 8.8 bolt for my gearbox input. I know of a different but very similar model where Kubota specifies a "Special grooved Gr. 8" bolt for the gearbox input. Owner's of that model might get away with a Gr. 5 or 8.8 in that location. On the other hand, Gr8 bolts are more likely to snap cleanly when they do go so while the plane bolt might shear at approximately the same force, the end might jam in the hole or cause damage to the edge of the shaft.

Personally, if I didn't have the specified replacement on hand (maybe the paperboy accidentally left two copies of the NY Times) I'd use a Gr2 and groove it to get by until I could restock and replace it with the proper one. It might not be the maximum allowable strength but better to be cautious than risk damage.

 

[SDT]

I was just looking up some prices of service items for the BX2816 / Bx2822 snow blower common service parts on Messicks dot com . The shear bolt part # 70060-01338 now costs $5.44 . Has Kubota lost all concept of reality, or is this a simple case of price gauging? When they were $2.00 a couple of years ago I thought that was on the high side.

The cost is in low volume distribution for the sake of convenience at your dealer, not piece price. You will find much the same everywhere.

 

[Blue2Orange]

Just back from the local ACE Hardware. Looking for a spare drive line shear bolt. Manual notes M8x50 Cl.6.6. Torque to 19 ft lbs. No luck. Assuming Cl6.6 is the grade? Kubota manual page og torque setting doesn't even list it. For metric IIRC they list 5.5 and 8.8 grade. Will stop by the dealer next time I'm close to it and pick one up for $??

Not going to have a "moment" if I end up paying a few dollars for something that I think should be a buck or two. Just our new "reality" regarding costs for goods and services.

On the old NH I have used just the proper grade basic hardware bolt. They can be a pita to remove the chunk stuck. The old blower pto connecting shaft knuckle shear bolt housing the bolt when using just a basic bolt always got stuck in the housing holding the nut and chunk of bolt. Real shear bolt. Don't remember an issue. When it sheared all sections of the bolt and nut flew or dropped out of the housing. Never remember having to remove the shaft and take it into a heated shop to putts around trying to remove it. Similar issue with the shear bolt on the rear knuckle that protects the gear box. That one occasionally required using a nail punch/setter to drive out the remaining chunk. PITA moments for being lazy and not replacing the emergency spare(aka normal bolt) until it breaks.

 

[Russell King]

Just back from the local ACE Hardware. Looking for a spare drive line shear bolt. Manual notes M8x50 Cl.6.6.

I think there may be a typographical error in your manual. I have never seen anything about a class 6.6 metric bolt. I guess anything is possible and they are getting special bolts with special strength but please post back what number is actually stamped on the Kubota shear bolt. I am just curious about this.

 

[Blue2Orange]

I think there may be a typographical error in your manual. I have never seen anything about a class 6.6 metric bolt. I guess anything is possible and they are getting special bolts with special strength but please post back what number is actually stamped on the Kubota shear bolt. I am just curious about this.

Yes, typo. Should read M8 x 50 Cl8.8 bolt. Manual notes torque to 19 ft lbs. Which is what the torque spec page in the manual notes for M8 x 1.25" 8.8 grade.

Bit inconvenient to access the driveline shear bolt with the knuckle guard in place. I guess lift to max height allowed (IIRC, 25 degree up), block it and access from bottom or unbolt the guard. Not recommended, but what I did on the old Loftness blower. Removed the guard and left off due to it obstructing easy access to the driveline shear bolt at the gear box end. No operator safety auto shut off on the NH. With the BX we have the added safety of auto shut down if moving the butt off the seat with the pto engaged. Probably a good thing with the aging forgetful mind.

Local Ace didn't actually stock any real shear bolts anymore. Too low sales. I guess most just purchased std bolts of proper grade to save couple dollars. I prefer real shear bolts. Will stock up next run to the dealer.

 

[North Idaho Wolfman]

Hey, your machine, your choice.

For a plain single shear plane style the manufacturer often specs a plain bolt. Kubota specifies a 1/4-20 Gr. 2 bolt for my auger and a 6mm 8.8 bolt for my gearbox input. I know of a different but very similar model where Kubota specifies a "Special grooved Gr. 8" bolt for the gearbox input. Owner's of that model might get away with a Gr. 5 or 8.8 in that location. On the other hand, Gr8 bolts are more likely to snap cleanly when they do go so while the plane bolt might shear at approximately the same force, the end might jam in the hole or cause damage to the edge of the shaft.

Personally, if I didn't have the specified replacement on hand (maybe the paperboy accidentally left two copies of the NY Times) I'd use a Gr2 and groove it to get by until I could restock and replace it with the proper one. It might not be the maximum allowable strength but better to be cautious than risk damage.

I had a friend that wanted some shear bolts made.
He picked up bulk grade 2 and grade 5 bolts of the right size and length.
He brought them over, with a stock one of each ,and I used the lathe and aa parting tool to cut the shear groves in them.