Snowblower Shear Pins question

[SailTrac]

I broke a LH shear pin on the blower (my left hand), and like others I have noticed a gap on the side of the auger and the bearing flange. The only way I could find the broken pin, was to remove the 3 bolts that hold the bearing flange on the left hand side and move the bearing flange to the right. If I leave the bearing flange to the right, there is a gap between bearing flange and sidewall of the blower. Its all put back together, the gap between the bearing flange and auger is there, and if I break another pin, the auger will go left and the fun starts all over.

So one of my questions is where is mis-alignment coming from? Was the blower not set-up correctly?
Something appears to be shifted to the right (my right) Hence the gap on the left. Do I make a spacer to fill the void between the bearing flange and sidewall of the blower to avoid the 45 min shear pin replacement time? Its either a bad setup or a bad engineering.
Does any one know whom makes these for Kubota?

Love that lake effect snow.

Thank you

Mike

 

[SPYDERLK]

Sounds as if the drive mechanism is shifted to the right. Maybe if you loosen all bolts holding it you will be able to move it to a better position and the tighten.
larry

 

[Dyer retired]

I broke a LH shear pin on the blower (my left hand), and like others I have noticed a gap on the side of the auger and the bearing flange. The only way I could find the broken pin, was to remove the 3 bolts that hold the bearing flange on the left hand side and move the bearing flange to the right. If I leave the bearing flange to the right, there is a gap between bearing flange and sidewall of the blower. Its all put back together, the gap between the bearing flange and auger is there, and if I break another pin, the auger will go left and the fun starts all over.

So one of my questions is where is mis-alignment coming from? Was the blower not set-up correctly?
Something appears to be shifted to the right (my right) Hence the gap on the left. Do I make a spacer to fill the void between the bearing flange and sidewall of the blower to avoid the 45 min shear pin replacement time? Its either a bad setup or a bad engineering.
Does any one know whom makes these for Kubota?

Love that lake effect snow.

Thank you

Mike

Mike,

I have a BX2750 blower (I couldn't find what your blower is, but suspect it's the 2750) and had the same thing happen for the last 5 years. The reason I'm assuming it's the 2750 is because the sheet metal is fairly thin and I found that my wings had bent slightly outward...causing the space you describe. The bearing collars have a set screw, but it's not meant to keep the bearing from being pulled sideways. I used some woodworking clamps to pull my wings back to where they should be and retightened the bearing collars, but the same thing happened all over again the next solid snow bank I ran into....and the pins were a bear to find when they broke. I measure the inner wing to inner wing and had 51", so 1" more than I should have had. Also, once the pin shears, it blends nicely with the shaft in all the grease that's in there, so it made it more problematic to find and replace. For a few years, I used a rubber mallet to strike the center gear housing (that's how the Kubota service repair guy did it one time when I was not having any luck changing the sheared pin out) to get the shaft to go in the direction I needed to find the hole again. I also tend to think that with the wing auger shaft and drive shaft pulling sideways against each other, might be causing the shear pin to fail all that much faster. I got sick of it, as it sounds like you are, and devised a fix. It's pretty primitive, but I haven't sheared a pin since I rigged it. The wings are exactly the same distance from the center gear housing and now measure exactly 50" from wing to wing. You can see what I did in the pictures, which essentially just holds the wings at the correct width. Disregard the top wire part of the fix, I was playing around with an alternative wire fix. I call it my $50.00 solution to my $1.00 problem, but it sure saves headaches. I can loosen the shear pin, pull it out and replace it by rotating the auger and lining up the holes.....as it was meant to do. If I break a pin, I rotate the auger and the sheared piece falls out on it's own now. I don't think the heavier gauge blowers like the 2781 and up have this problem? Dyer, retired

 

[SailTrac]

Dyer, retired,

I should have said that I have the BX2750 blower on my BX2200. I never would have thought about the sheet metal bending. However, looks like the tape measure needs to come out and see what's what. Base on your photo's, you have wire at the top, and it appears another bar at the bottom. You must have found that you needed both, yes? Your remedy is definitely food for thought.

You are right about being tired of searching for broken shear pin. Last year was a two adventure, and the one I broke on Saturday was another 2 hours of laying of head scratching. I even came here to see if I could find a quicker fix.

Thank you for quick response, and I will follow up with my fix!

Its 4:08pm here, snowing, Route 104 in the town of Oswego has been shut down due to an accident...

Mike

 

[Dyer retired]

Dyer, retired,

I should have said that I have the BX2750 blower on my BX2200. I never would have thought about the sheet metal bending. However, looks like the tape measure needs to come out and see what's what. Base on your photo's, you have wire at the top, and it appears another bar at the bottom. You must have found that you needed both, yes? Your remedy is definitely food for thought.

You are right about being tired of searching for broken shear pin. Last year was a two adventure, and the one I broke on Saturday was another 2 hours of laying of head scratching. I even came here to see if I could find a quicker fix.

Thank you for quick response, and I will follow up with my fix!

Its 4:08pm here, snowing, Route 104 in the town of Oswego has been shut down due to an accident...

Mike

Mike,

The wire at the top of the photo was a backup and really just experimentation more than anything. The bar at the bottom is just a 1/2" threaded bar. I've run two more steel square stock pieces down from the center support exactly in the middle of the unit and that allowed me to draw each side in kind of independently to the right measurement.

In the meantime, the rubber mallet works fine. I've been able to change shear pins out in 5 minutes before, but it was usually taking 20 minutes. I'd have to spray the shear pin hole with engine degreaser, so that I could see the outline of the sheared piece in the drive shaft, pound the mallet to get the holes to line up exactly (that pin won't come out otherwise...even if off a little) and then I'd use a nail set to tap the pin out. And of course, it's never convenient when the pins shear and I could never change the things with gloves on, so it would be a nice hand numbingly cold experience to add to the fun.

The wings don't flex out much, but as you are finding out, it doesn't take much to cause you a headache changing those things out. Dyer, retired

 

[lakeside]

I have a G1800 with a 2546 blower. The blower is about 15 years old and they must have made the blowers out of thicker metal back then as I haven't had a problem with bending wings. But, I did shear a few auger shear bolts when I was clearing my cottage driveway. The cause was gravel getting sucked up into the blower. There I was, stuck late on Friday night 40 km from the nearest (and now closed for the weekend) dealer.

I took a large common nail that just fit the shear bolt hole and used that as a temporary fix. In fact, I used the nail for a few weeks. In the mean time I'd bought the proper bolt and just never got around to replacing my "temporary" fix. Another Friday night and the nail sheared. It proved the nail sheared before damage occurred. I wouldn't recommend using anything but an approved shear bolt, but when you're stuck. I would NOT recommend using a normal bolt unless you want twisted or broken drive shafts. Shear bolts, like fuses, are a built-in weak point to prevent other, most costly damage.

 

[Dyer retired]

I have a G1800 with a 2546 blower. The blower is about 15 years old and they must have made the blowers out of thicker metal back then as I haven't had a problem with bending wings. But, I did shear a few auger shear bolts when I was clearing my cottage driveway. The cause was gravel getting sucked up into the blower. There I was, stuck late on Friday night 40 km from the nearest (and now closed for the weekend) dealer.

I took a large common nail that just fit the shear bolt hole and used that as a temporary fix. In fact, I used the nail for a few weeks. In the mean time I'd bought the proper bolt and just never got around to replacing my "temporary" fix. Another Friday night and the nail sheared. It proved the nail sheared before damage occurred. I wouldn't recommend using anything but an approved shear bolt, but when you're stuck. I would NOT recommend using a normal bolt unless you want twisted or broken drive shafts. Shear bolts, like fuses, are a built-in weak point to prevent other, most costly damage.

lakeside,

I should clarify that the wings bending out didn't cause the pins to shear, but I suspect that the added side pulling stress didn't help much. I was shearing pins the old fashioned way, hitting ice chunks, hidden tree branches, good old rocks, etc. I think the bigger rocks may have caused enough of a jump to the auger shaft that it pushed the wings a little just before the bolt sheared. The problem was that when the wings shifted and a pin sheared, it was very difficult to line up the auger shaft with the inner drive shaft hole, which is what SailTrac is experiencing. I was shearing enough pins in my first year with the blower from hitting everything imaginable, that I made sure to keep a big supply of shear bolts on hand. Dyer, retired

 

[FullBucket]

Just thought I'd throw in a shear pin tip the dealer showed me. Use electrical tape to attach a spare pin on the arms that connect to the 3 point hitch. Handy place to find one when you need it.

 

[whatever1]

So far I have been lucky and have not bent out the wings....

As long as we are getting out the measuring tape I have a question. On my blower it looks like there is a larger than normal gap between the auger and the back of the blower. Today when I finished the driveway there was a layer of wet snow in the back that the auger did not move. Could they be worn down ? Is there an adjustment to move the augers in closer ?

Thanks

 

[huckflynn]

So far I have been lucky and have not bent out the wings....

As long as we are getting out the measuring tape I have a question. On my blower it looks like there is a larger than normal gap between the auger and the back of the blower. Today when I finished the driveway there was a layer of wet snow in the back that the auger did not move. Could they be worn down ? Is there an adjustment to move the augers in closer ?

Thanks

For the eight+ years I have been using my blower there has almost always been a thin layer of wet snow in the back when I am finished. I never considered it a problem.

 

[Dataway]

I think that gap is normal, all the 2750's I've seen has it.

I noticed something a bit strange on my 2750. The main input shaft where it attaches to the thrower itself has a shear bolt.... AND ...a key in the shaft. Seems like the shear bolt is a bit useless if the shaft is keyed and the key is installed (as it was on my machine).
JohnnyB

 

[Dyer retired]

For the eight+ years I have been using my blower there has almost always been a thin layer of wet snow in the back when I am finished. I never considered it a problem.

Mine gets that same layer, but after the first use a couple of days ago, there is a nice layer of just plain dirt back there. I sure like it better when the ground freezes up. Dyer, retired

 

[Dyer retired]

I think that gap is normal, all the 2750's I've seen has it.

I noticed something a bit strange on my 2750. The main input shaft where it attaches to the thrower itself has a shear bolt.... AND ...a key in the shaft. Seems like the shear bolt is a bit useless if the shaft is keyed and the key is installed (as it was on my machine).
JohnnyB

Dataway,

I have a shear bolt on my fan shaft, which is a smaller and shorter shear bolt than the ones in the auger shaft. That fan shear bolt is in front of the fan and is kind of a pain to replace, only because it's hard to get a wrench on the nut. I can't picture the key you are describing on that shaft? I've sheared my fan bolt in the past (much less frequent than the auger bolts) and it worked as it was designed to do. Any chance you could identify the key woodruff with a picture or part number? I'm curious now. John

 

[Dataway]

I couldn't find a good pic, or part number...the basic parts breakdown I have for the mid-pto doesn't show the bolt or the pin.

If you follow the drive shaft from the tractor to the thrower, just forward of the universal joint under the drive guard, where the shaft enters the drive sprocket area, you'll see the connection between the drive shaft and the thrower drive sprocket (under the metal guard). The front section of the universal slides on a plain keyed shaft, the keyed shaft goes through the lower fan drive sprocket. The front half of the universal is both keyed, and shear bolted to the lower fan drive sprocket shaft (all this stuff is on the tractor side of the thrower unit).

Now that you mention that the fan is shear bolted to it's shaft, the only thing the shear bolt/key I mention is isolating is the chain drive section. Still....kinda useless with the key still installed.

Point me to a good parts diagram of the 2750 and I can give you a part number.
JohnnyB

 

[kevinj]

I couldn't find a good pic, or part number...the basic parts breakdown I have for the mid-pto doesn't show the bolt or the pin.

If you follow the drive shaft from the tractor to the thrower, just forward of the universal joint under the drive guard, where the shaft enters the drive sprocket area, you'll see the connection between the drive shaft and the thrower drive sprocket (under the metal guard). The front section of the universal slides on a plain keyed shaft, the keyed shaft goes through the lower fan drive sprocket. The front half of the universal is both keyed, and shear bolted to the lower fan drive sprocket shaft (all this stuff is on the tractor side of the thrower unit).

Now that you mention that the fan is shear bolted to it's shaft, the only thing the shear bolt/key I mention is isolating is the chain drive section. Still....kinda useless with the key still installed.

Point me to a good parts diagram of the 2750 and I can give you a part number.
JohnnyB

I do not think that is supposed to be a shear joint. The shaft is retained by the bolt and drives on the key. The 2750 has 3 shear bolts as I recall, two on the augers and one on the impeller.

 

[Dyer retired]

I do not think that is supposed to be a shear joint. The shaft is retained by the bolt and drives on the key. The 2750 has 3 shear bolts as I recall, two on the augers and one on the impeller.

Dataway,

kevinj is correct and the bolt you are referring to is not a shear pin. That sprocket keeps turning when the fan pin is sheared, but does not hurt anything. You'll see on the front of the blower just in front of the fan two shear plates that come together with a small shear bolt connecting them. When the fan gets snagged somehow, the little shear bolt cuts off and no harm done. That little bolt is miserable to change, because there isn't much room to turn a wrench behind it and they make the bolts about an inch longer than they need to be. I bought a supply and cut the extra inch off, so when I need to replace one (which isn't often on the fan unit) I don't spend all day trying to thread the distance with the self locking nuts. I just looked at my neighbor's BX2750D and they've corrected the problem with the fan shear bolt to make it easier to change. I can scan a part diagram of the blower and send it, but not sure if it will be readable....I'll try it though. John

 

[Dataway]

I understand perfectly now, makes sense...I didn't consider that the bolt was a retaining device....but now that I'm thinking clearly...yeah the collar would just slide off the keyed shaft without something holding it on.

It was what is known as a Gross Misconceptual Error.
Thanks,
JohnnyB

 

[Dyer retired]

I understand perfectly now, makes sense...I didn't consider that the bolt was a retaining device....but now that I'm thinking clearly...yeah the collar would just slide off the keyed shaft without something holding it on.

It was what is known as a Gross Misconceptual Error.
Thanks,
JohnnyB

JohnnyB,

I sent these for your files....it didn't sound like you had them? They aren't the best of quality, but I think you can read them o.k. John

 

[whatever1]

I spoke too soon. This year I managed to flare out the sides of my blower. The only difference is this past year I had my drive blacktopped. While blowinging instead of leaving it in the float position I put a little down force to scrap the driveway. This is the only difference in operation and was enough to flare out the sides.... Any thoughts ???

 

[SPYDERLK]

I have a G1800 with a 2546 blower. The blower is about 15 years old and they must have made the blowers out of thicker metal back then as I haven't had a problem with bending wings. But, I did shear a few auger shear bolts when I was clearing my cottage driveway. The cause was gravel getting sucked up into the blower. There I was, stuck late on Friday night 40 km from the nearest (and now closed for the weekend) dealer.

I took a large common nail that just fit the shear bolt hole and used that as a temporary fix. In fact, I used the nail for a few weeks. In the mean time I'd bought the proper bolt and just never got around to replacing my "temporary" fix. Another Friday night and the nail sheared. It proved the nail sheared before damage occurred. I wouldn't recommend using anything but an approved shear bolt, but when you're stuck. I would NOT recommend using a normal bolt unless you want twisted or broken drive shafts. Shear bolts, like fuses, are a built-in weak point to prevent other, most costly damage.

As you said, a shear bolt is a modified bolt. You pay highly for this. I instead, use fully threaded bolts of the same grade as the oem shear bolt. The thread cut serves the built in weak point function at a cost at McMaster-Carr of 1/10 or less the std one.
larry