Replacing auger shear bolts - B2782

[irvingj]

Ditto PILOON... I keep a small box on the tractor, which has in it spare shearpins, a tapered, flat-faced punch, paper towels, 7/16" socket/ratchet, 7/16" box-end wrench, and a small hammer.

First year I used the blower I never broke a pin... now I can count on losing at least a few every winter!

It also seems to make a big difference if I follow the manual- and only use 9 ft-lbs of torque, basically just enough to snug up the lockwasher. At first I wound 'em right in there, but that did seem to hasten the breakage.

 

[Haywire]

Do they make blowers with slip clutches like are found on tillers?

 

[leonz]

Hello Ian,

No one makes make blowers with slip clutches

for residential or commercial use.

The business end of a snow blower

being the auger is always subject to

the forces created by the rotation

of the cross auger halves and the

shear pins are the simplest way to

protect the 2 stage snow blower

that employs the open auger

configuration rather than a solid auger

ribbon using a gearbox after the V belt

drive or paddle auger which is typically

belt driven.
.


You can use a friction disc liimited slip

clutch successfully on a rear blower when the

bottom 4 inches of the intake is protected

with a meshed frame of concrete reinforcing

mesh to prevent cobbles from entering the

the housing and shearing the pins in which

I described to a member earlier in the

week that was dealing with constantly breaking

shear pins due to his access road to hos home

being subject to ice if any wet snow is left on

his dirt road to his home which is a very high

elevation and fully exposed to high winds and

thus quickly freezing snow turning it to ice.

 

[kday64]

All,

I am a bit confused. I own a B2789 that is mounted on the back of a BX2360. They are awesome machines. Oh yeah I snapped my first shear pin of the season and first shear pin on this tractor.

I opened the manual and it showed two shear pins. One in the Driveline and one in the DriveShaft. I snapped the driveline shear pin. Easy fix, 5minutes... first time ever.

Both of these pins hold two plates together. There is very little lining up required especially if one disconntects the driveline from the PTO. Or are you all talking about the rear bolt on the driveline?? If so I don't think this is a shear pin at all. The rearpin on my driveline is a gr12 bolt.

Below are the required shear pins for my B2789.
The driveline shear pin is a M10 x 1.25" x 45mm gr8.8 bolt.
The drive shaft pin is 5/16" NC x 1.75" gr5 bolt.

~Kevin

 

[Sumpter]

I have never found any remnants of my shear bolts when they go. They seem to evaporate.

 

[kday64]

I have never found any remnants of my shear bolts when they go. They seem to evaporate.

I also found this to be true. Though I have only snapped on shear pin on my BX. I use to shear bolts/pins all the time back home on my family's Ford. (I was too young to understand that I needed to step off the clutch slowly.)

When I was growing up my brothers and I snapped the rear bolt at the universal joint. This bolt is not a shear pin and is a pain to line up, punch out and replace. This bolt should be gr12 bolt to ensure the gr8/gr5 shear pins snap first.

~Kevin

 

[Haywire]

Gr 12? I didn't know it went above 8. :shrug: I learn something new every few years.

 

[kday64]

Gr 12? I didn't know it went above 8. :shrug: I learn something new every few years.

Bolt Depot - Bolt Grade Markings and Strength Chart

I didn't know there was anything higher than a gr8 until went out and examined the driveline more closely and realized the head of a bolt said 12. From my reading of wikipedia gr12 is not a steel alloy.

There is very little on the topic of gr12 bolts... I wonder why? Not many uses.

~Kevin

 

[Haywire]

It looks like the metric bolt grades are stronger than the imperial equivalents. Metric "classes" being 8.8, 10.9, 12.9 and imperial "grades" being 2, 5, 8.

It isn't a numerical continuation.. class 8.8 isn't stronger than grade 8.

Edit... a bit of conversion of units.. "proof loads" in psi. Grade 5 and Class 8.8 are very similar, Class 10.9 is just a hair over grade 8.

Grade 2: small bolts 55k, bigger bolts 33k
Class 8.8: small bolts 84k, bigger bolts 87k
Grade 5: small bolts 85K, bigger bolts 74k
Grade 8: 120k
Class 10.9: 120.381k
Class 12.9: 140k

 

[Dyer retired]

I use a similar method as Ductape...I try to clean the grease out of the way to better see the sheared bolt remaining, but I just spray degreaser and then do a quick swipe with a paper towel. My B2782 doesn't seem to shift like my old 2750 where you had to move the wings to get the shafts to line up, so you could then punch out the remaing bolt.

As AJL mentioned, I sheared an impellar bolt and found no reason for it, but that's a much easier changout on the 2782.