Shear bolt breakage ???

[etcallhome]

Just wondering, I bought 47" blower used this fall and so far I have replaced 15-20 grade 5 bolts.....OK about 12-15 probably my fault...Going in to frozen snow , doing edge of road .
2/3 of bolts I have replaced is on the right side. Only 2 on 2nd stage 1 yesterday my fault not running rpm high enough and in some wet snow, clogged up shoot.
I noticed that left side has a shorter auger shaft compared to right side.
I ran blower with right side broken and went in the same snow pile that had broken shear bolt on the right side. Blew snow and ice for 15 min or more before I replaced the right side.
So I'm thinking the longer shaft right side , more snow to move is the reason for me breaking more shear bolts on right compared to left.
I love the snow blower yes some vibration , will check set screws ,chain and ujoint aliment .
Moved a pile of snow yesterday about 70' in length , 4 ' high and about 6' deep.
Thanks for all replies in advance

 

[Henri88]

Hi! I had the same problem when I first got my blower. When I broke my first shear bolt, I read in the manual not to overtightened them. Broke 3 more in 2 days. I then realize that the bolt were getting loose, which made the auger noisier and eventually broke the bolt. Now I put them nice and tight making sure not to overtightened them to the point they would break, and after each snowfall I check them by moving the auger by hand to see if there is any loose bolts. Only broke one since with a chunk of ice.

 

[sunnyside360]

Wow, how in the heck are you guys snapping these shear bolts? I have over 1000 ft of driveway to clear and I had a 47 snow blower for 5 yrs on an X485 tractor and never broke a bolt. It also ran very smooth with no vibration whatsoever. In fact, if no snow was flying out the chute you couldn't tell if the blower was running or not.

 

[beenthere]

Better the shear bolts break, than break the auger.

Ice is like a rock, and either chew through it slow, or break a shear pin. That is the limit of the snowblower. Cant bulldoze ice out of the way. Maybe the vibration is from a bent part in the impeller or the auger. ??

One good reason I chose a blade over a blower. Blower is too slow (for me).

 

[sal64]

try an allen head bolt the original allen name its much stronger.

 

[Henri88]

Wow, how in the heck are you guys snapping these shear bolts? I have over 1000 ft of driveway to clear and I had a 47 snow blower for 5 yrs on an X485 tractor and never broke a bolt. It also ran very smooth with no vibration whatsoever. In fact, if no snow was flying out the chute you couldn't tell if the blower was running or not.

It all depend on the kind of snow or driveway your doing. Last year in December, we received some snow followed by rain and then -15 C. Perfect cocktail to have chunk of ice in your driveway when the city plow decide to widen the street 6 days later. But this is not the issue, what is, is that your shear bolt do what there suppose to do, break before the gear pinion does. If in 5 yrs you never blow any hard icy snow or if your driveway is all pave no rock, then all is well, but if this is not the case, I would have a look at the grade of those shear bolt. Better be safe than sorry.

Sal 64, the recommended grade is very important. I always feel good when I catch something hard, and the bolt brakes. I know it did its job.

 

[etcallhome]

Well worked on snow blower today and the left side the nut was very loose.
also found the set screws were loose on the right side.

Also the front bolt for the shoe was within 1/16 or less of touching auger as it was spinning. Turned that bolt around and put nut on the outside of blower.

Also where back propeller and shaft come together I noticed the set screw is missing I will need to get one (well 2 or 3 ) of these. But nothing seems to be moving to get things out of adjustment.

Noticed someone said they never broke a shear bolt. Must not have county or state road come along and plow back the roads...
The other night I was out blowing snow for close to 3 hrs. As long as I was on fresh snow day or two old never sheared a bolt.

 

[johnamon]

As beenthere said, shear bolts or pins are designed to break as a specific point to protect both upstream and down stream parts. Be sure to replace them with the same type, nothing stronger.

We have had our tractor / snow blower for three years and have never broken a shear bolt. I am a little afraid to say that I will jinx myself.

In use I have very little vibration in the snow blower except if I raise it too high when running. Then the universal joints complain.

John

 

[Henri88]

Well worked on snow blower today and the left side the nut was very loose.

etcallhome, tight does nuts nice and snug and keep an eye on them, you will see a big difference. It will eliminate some noise also. It sure did with mine.

 

[kennyd]

Add some Loctite to those set screw also when you replace them.

 

[sunnyside360]

It all depend on the kind of snow or driveway your doing. Last year in December, we received some snow followed by rain and then -15 C. Perfect cocktail to have chunk of ice in your driveway when the city plow decide to widen the street 6 days later. But this is not the issue, what is, is that your shear bolt do what there suppose to do, break before the gear pinion does. If in 5 yrs you never blow any hard icy snow or if your driveway is all pave no rock, then all is well, but if this is not the case, I would have a look at the grade of those shear bolt. Better be safe than sorry.

Sal 64, the recommended grade is very important. I always feel good when I catch something hard, and the bolt brakes. I know it did its job.

I understand now -- large ice chunks can/will create havoc in a snow blower. I guess if you have no choice then you have to do it. I saw how my neighbor destroyed his snow blower on his long driveway so I use a snow blade (plow) to clear ice pieces and the snow blower to clear snow from the driveway. On occasion, I've even resorted to using a dozer when necessary. And, yes my driveway is paved so near zero risk of catching a rock.

 

[Henri88]

Add some Loctite to those set screw also when you replace them.

Darn! Never thought of that one. Thanks Kennyd.

 

[mjncad]

Just wondering, I bought 47" blower used this fall and so far I have replaced 15-20 grade 5 bolts.

Does that blower really use Grade 5 shear bolts? That's a tough bolt.

Are you using bolts that are threaded all the way, or just part way? Make sure to use partially threaded bolts unless the manual states otherwise as they are stronger since the bolt shank is the full nominal diameter.

 

[etcallhome]

Thanks Kennyd I had thought of using Loctite .

mjncad Are you using bolts that are threaded all the way, or just part way? Make sure to use partially threaded bolts unless the manual states otherwise as they are stronger since the bolt shank is the full nominal diameter.

I have been using threaded all the way....But I will change to the partially threaded bolts ,,,I hadn't thought about them being stronger.

 

[turbo36]

The vibration from the poorly designed driveline is causing the shear bolts to loosen and break. I'm sure that's the reason for the other fastener issues also. I ran my 47" on the 455 for years without a problem but when it went on the 2305 I would constantly break shear bolts for no reason. I got in the habit of checking the tightness of all the bolts on the blower before and after every use; this solved the problem but what a pain in the butt.
My love affair with the 2305 faded after a couple of years of this and I replaced it with a X749 to do the mowing and blowing and a 2520 to do everything else. The blower was so smooth on the X749 you could hardly tell it was working; no broken or loose bolts either. I switched this year to the new 54" and that is very smooth also.

 

[radman1]

Add some Loctite to those set screw also when you replace them.

The shear bolts on my 3pt blower use lock nuts. Could use lock nuts if don't have Loctite.

 

[kennyd]

The shear bolts on my 3pt blower use lock nuts. Could use lock nuts if don't have Loctite.

Read again...He was talking about set screws...no nuts on them

 

[etcallhome]

Kennyd I did put loctite on the set screws today. I also changed the all thread and put in partial thread with nylon lock watchers.
Now just need to wait for some snow to give everything a try.

 

[kennyd]

Kennyd I did put loctite on the set screws today. I also changed the all thread and put in partial thread with nylon lock watchers.
Now just need to wait for some snow to give everything a try.

Good. I hope you have a long wait...

 

[Wildbill34]

Ocassional shear bolt breakage is normal. However, I too went through a lot of shear bolts last year. Found I had some excessive vibration with the shaft and I also used loctite on the shear bolts and the problem disappeared. But mine was with the impleller fan and not the auger. Although I have lost auger shear bolts, it was due to trying to move mounded snow and I shouldn't really have attempted it or I picked up some ice when I didn't snow blow the driveway originally after a snow.