Snowblower Help - Eating Shear Bolts

[River19]

Could use some help.......I have a BX2830 48" blower and it has been flawless in 3 seasons however towards tail end of our epic 38" snow storm a couple weeks back I hit a piece of tree debris and broke a shear bolt on the impeller. No big deal, have plenty.......installed a new one......that one broke in less than 50' of blowing. Great.

I went back out this morning to blow back some drifts after they have been softening in the sun.....I have booked 4 bolts TODAY in less than 30' of actual blowing and I'm not hitting anything but snow and nothing near what I have put this blower through in the past 3 seasons.

What am I doing wrong.......it has to be something stupid. I might be over tightening them......seeing as how the last one I literally broke in the socket installing it.

Here's what I am doing......first the impelling spins very freely so it isn't binding. Nothing is off on the augers and they are properly offset.

I line up the damn holes, put the bolt in from the "back" or impeller side, I've put the crush washer on either side thinking that I might have done THAT wrong, then I thread the bolt on......tighten up and fire it up......within 30seconds...."clunk clunk".....snow stops blowing and here we are.......

Am I over tightening the bolts? Should I really put a torque wrench on these things? I have replaced this bolt before and it has lasted over a season so something is up......

HELP!!!! Thoughts?

P.S. The bolts are all factory from Messicks

 

[yorkies77]

Could use some help.......I have a BX2830 48" blower and it has been flawless in 3 seasons however towards tail end of our epic 38" snow storm a couple weeks back I hit a piece of tree debris and broke a shear bolt on the impeller. No big deal, have plenty.......installed a new one......that one broke in less than 50' of blowing. Great.

I went back out this morning to blow back some drifts after they have been softening in the sun.....I have booked 4 bolts TODAY in less than 30' of actual blowing and I'm not hitting anything but snow and nothing near what I have put this blower through in the past 3 seasons.

What am I doing wrong.......it has to be something stupid. I might be over tightening them......seeing as how the last one I literally broke in the socket installing it.

Here's what I am doing......first the impelling spins very freely so it isn't binding. Nothing is off on the augers and they are properly offset.

I line up the damn holes, put the bolt in from the "back" or impeller side, I've put the crush washer on either side thinking that I might have done THAT wrong, then I thread the bolt on......tighten up and fire it up......within 30seconds...."clunk clunk".....snow stops blowing and here we are.......

Am I over tightening the bolts? Should I really put a torque wrench on these things? I have replaced this bolt before and it has lasted over a season so something is up......

HELP!!!! Thoughts?

P.S. The bolts are all factory from Messicks

The shear bolts need to be torqued to 8 pounds. I broke a lot before I found that out.

 

[River19]

The shear bolts need to be torqued to 8 pounds. I broke a lot before I found that out.

I'll bust out the torque wrench this afternoon and try 8lbs......thanks, I will report back.

 

[Russell King]

If the bolts have been undercut then they will be easier to break and having much tightening force on them will make it so they’re already near or at their breaking point of stress.

both the stretching force and pure shear can break the bolt and also the combination of the two can break the bolts.

you probably know this stuff so can just call me Captain Obvious

 

[River19]

OK, I have something else going on here then. I just went through another 2 bolts that were barely over hand tight.

Here's what I checked:

1. Without the bolt, impeller spins nice and freely
2. Put in bolt.....disconnected the PTO shaft and the auger & impeller spin nice and easy as they should
3. Augers are offset properly 180 degrees from each other
4. I checked to make sure nothing is bent or binding....also felt no binding when spinning
5. It will work "fine" for 1 minute or so.....as soon as any real load gets on it I get a clunking and shaking like it is eating large chunks of ice or rocks (which it isn't) and then boom.....bolt breaks. Almost like something in the gear box is messed up and under load it binds enough to cause the bolt to break.

I am at a loss.......

Without a magical cure I will call my dealer......

 

[DustyRusty]

Take the shear bolts out of both sides and spin the augers. They should turn freely with no binding. Then do the same thing with the fan to make sure there is no binding in the fan. You could have damaged your gearbox, but it is unlikely, however, something has to be out of alignment. With the 2 shear bolts still out of the augers, start the machine and engage the snowblower, and observe the augers. They shouldn't be turning much if at all. If one is turning and the other is not, then possibly the shaft has a bend in it. If your tractor has a seat cut off, you will need someone to sit on the seat while you observe the augers. Keep your hands away from the augers when the machine is running, even though there are no shear bolts installed.
I hit a large rock once and bent the auger and the fan, and after I took it apart and hammered everything back in place I never had a shear bolt problem, but it did vibrate quite a bit. A new fan would have cured that, but I sold it instead and got a new tractor and snowblower.

 

[River19]

Take the shear bolts out of both sides and spin the augers. They should turn freely with no binding. Then do the same thing with the fan to make sure there is no binding in the fan. You could have damaged your gearbox, but it is unlikely, however, something has to be out of alignment. With the 2 shear bolts still out of the augers, start the machine and engage the snowblower, and observe the augers. They shouldn't be turning much if at all. If one is turning and the other is not, then possibly the shaft has a bend in it. If your tractor has a seat cut off, you will need someone to sit on the seat while you observe the augers. Keep your hands away from the augers when the machine is running, even though there are no shear bolts installed.
I hit a large rock once and bent the auger and the fan, and after I took it apart and hammered everything back in place I never had a shear bolt problem, but it did vibrate quite a bit. A new fan would have cured that, but I sold it instead and got a new tractor and snowblower.

I'll try that this week.

Heck, the impeller bolt is gone again anyways lol.

Glad this happened late season thankfully, but I need to get this sorted.....I just fought a 5' by 40' pile of snow with my Honda tracked blower and my arms are toast.....

 

[jimh406]

Have you checked the chain tighteness or anything else that could be loose?

 

[River19]

Have you checked the chain tighteness or anything else that could be loose?

No chain on the BX2830......center gear box, but checking the chain etc. is a logical thought on other blowers. There is just no real slop on the commercial blowers but here I am eating $0.50 bolts like candy......

I will pull the auger bolts later today to see if the axle is binding in the auger which sounds like it would suggest a bend axle......

I appreciate all the suggestions

 

[River19]

Take the shear bolts out of both sides and spin the augers. They should turn freely with no binding. Then do the same thing with the fan to make sure there is no binding in the fan. You could have damaged your gearbox, but it is unlikely, however, something has to be out of alignment. With the 2 shear bolts still out of the augers, start the machine and engage the snowblower, and observe the augers. They shouldn't be turning much if at all. If one is turning and the other is not, then possibly the shaft has a bend in it. If your tractor has a seat cut off, you will need someone to sit on the seat while you observe the augers. Keep your hands away from the augers when the machine is running, even though there are no shear bolts installed.
I hit a large rock once and bent the auger and the fan, and after I took it apart and hammered everything back in place I never had a shear bolt problem, but it did vibrate quite a bit. A new fan would have cured that, but I sold it instead and got a new tractor and snowblower.

DustyRusty........I just did this.

Pulled the 2 auger shear bolts (impeller is already out) so no bolts at all. One auger spins smoothly and easily by hand, the other spins but not easily, it is binding......

I setup my phone on video and fired up the PTO and brought the throttle up about half way and I could see both augers moving almost at regular speed if not full speed......but what I also noticed as I took it to half throttle......pulsating that normally isn't there, to the point the tractor starting gently bouncing with the shake.......

Feels like bent axle to me...........thoughts?

 

[DustyRusty]

Take it apart and check the shaft. You will need to press it out from the gearbox. There are a few videos on YouTube showing people removing the shaft. Depending on how bent it is, will determine if a good machine shop can straighten it. It has to be straightened cold so as not to ruin it. A new one is Part # 77700-09972 and the cost is $91.26 and about 5-10 business days to get one in stock at Messicks dot com. I would check with MB Tractor since they have an excellent inventory of parts in over 9 stores. When I needed a part this past winter and Messicks didn't have it in stock, and after calling all the dealers around me, I hit upon MB Tractor they had it in stock, and they shipped it to their local store in CT from the store in NH. Had it a few days later.

 

[River19]

Take it apart and check the shaft. You will need to press it out from the gearbox. There are a few videos on YouTube showing people removing the shaft. Depending on how bent it is, will determine if a good machine shop can straighten it. It has to be straightened cold so as not to ruin it. A new one is Part # 77700-09972 and the cost is $91.26 and about 5-10 business days to get one in stock at Messicks dot com. I would check with MB Tractor since they have an excellent inventory of parts in over 9 stores. When I needed a part this past winter and Messicks didn't have it in stock, and after calling all the dealers around me, I hit upon MB Tractor they had it in stock, and they shipped it to their local store in CT from the store in NH. Had it a few days later.

My dealer is Chappell Tractor, similar to MB, both are here in NH.....I will get on the horn with them tomorrow. I watched a couple vids and while I could do the bulk of the work, I would need to purchase a bearing puller etc. and I need to weigh the time it would take to deal with this against the fact I have 21 trees that came down during this past 38" snow storm that I need the time to deal with vs. screwing around with the blower. Might need to just have the dealer grab the unit so I can move on with what I actually need the tractor for right now......

Glad it happened at the end of the season......

I really appreciate your help (as well as others who chimed in) to diagnose things, I'm 98% sure it is the axle/output shaft.

 

[DustyRusty]

Chappel is also a great dealer. My snowblower came from them. The only thing that I don't like about Chappel is the giant stickers that they put on everything that they sell that is next to impossible to remove. I hated when the car dealers would put their name stickers on the deck lids of the cars also.

 

[GreensvilleJay]

heat gun and gently pull the sticker off....
or take to a 'body shop' or 'sign shop' ! They KNOW how to get them off.
I took the metal 'dealer' plate holder off my new ride and sales guy was upset,told him unless the dealership was going to pay me, MY MONTHLY fee, I will NOT be advertising for them.

 

[DustyRusty]

I know, but I'm old and lazy!

 

[BAP]

I’m not sure that a very slightly bent auger shaft is your problem with your fan shear bolts. I think you are going to find that you are throwing parts towards a problem without it curing it. If it is bent so slightly that you can’t really tell it’s bent, then maybe it isn’t a problem. Plus, how can a slightly bent auger shaft cause the fan shear bolt to shear? I think that you need to be looking for something that is with the fan itself. Check mounting bolts for all fan drive components to make sure nothing is loose or has moved. Should be able to see any movement in bolts by looking at the paint. Put all your shear bolts back in and run it again while running it to see if you get the same pulsing and shaking. Could possibly be a bent fan shaft or drive shaft to the fan. Yes, the bent auger shaft could be a problem down the road, but unlikely it is your fan problem. Something directly with the fan is your problem.

 

[River19]

I’m not sure that a very slightly bent auger shaft is your problem with your fan shear bolts. I think you are going to find that you are throwing parts towards a problem without it curing it. If it is bent so slightly that you can’t really tell it’s bent, then maybe it isn’t a problem. Plus, how can a slightly bent auger shaft cause the fan shear bolt to shear? I think that you need to be looking for something that is with the fan itself. Check mounting bolts for all fan drive components to make sure nothing is loose or has moved. Should be able to see any movement in bolts by looking at the paint. Put all your shear bolts back in and run it again while running it to see if you get the same pulsing and shaking. Could possibly be a bent fan shaft or drive shaft to the fan. Yes, the bent auger shaft could be a problem down the road, but unlikely it is your fan problem. Something directly with the fan is your problem.

Fair point.

That being said.....with all shear bolts removed, one of the augers spins nice and smoothly, while the other clearly binds. When I turned the PTO on with the shear bolts out I expected the output shaft/axle to spin freely while the auger lazily rotate........they basically rotated at normal speed.......

I'm not 100% sure of what is wrong......but I do know the vibration is new, and clearly it is snapping that fan bolt within seconds of having a load on it.

 

[River19]

Quick Update:

I sent the video to my dealer of the blower running without shear pins and he literally went frame by frame (awesome guy) and noticed one of the augers appears to be making contact with the impeller, so something is most likely bent and wonky.

 

[Jchonline]

Quick Update:

I sent the video to my dealer of the blower running without shear pins and he literally went frame by frame (awesome guy) and noticed one of the augers appears to be making contact with the impeller, so something is most likely bent and wonky.

Wood can do that. My dog loves to leave large sticks (I mean like 6 inch diameter) in the road. Yes he has the "big stick" complex. Before it snows I have to inspect the 1 mile road and make sure there are none I will run over.

 

[DustyRusty]

Get an estimate of the repair cost from the dealer before they dig into it. Having them fix it might be a lot more than you think. A lot depends on how much they charge an hour, and how fast or slow the tech will do the job. I can see them charging you for 10 hours of labor and who knows what for parts. I would pull it apart myself when I have time rather than have them rake you over the coals. If you have KTAC insurance, let them deal with it. Most likely they will call it a total loss and give you another one. That is how I bought mine. It was considered a total loss and sold to the high bidder that fixed it and then sold it to me.