snapped chain.....twice

[Sumpter]

We have snapped the chain twice on the new blower. The shear bolts are Grade 5 - 5/16" which is recommended. Both times it has been a rock. I wonder it I need softer bolts or a stronger chain. My belief is that the bolt should shear before the chain breaks. The bolts broke the first time the chain broke but not the second time. Any suggestions?

 

[Thomas]

"My belief is that the bolt should shear before the chain breaks."
Correct,once in great while chain will snap.

I would seek out stronger chain leave shear pins size as is also take walk about remover the bigger stones.

 

[ihuntbear]

Rock are hard on chains.do you know if the chain is 60 or 60h.The 60h is a thicker and heavier chain.Mine has 60h.Any chain store should have some.Usualy if the chain breaks there is most likely a crack some where else or its streached.I always change mine .Chain is cheap

 

[Sumpter]

I do not know what chain I have. I will have to check it.

 

[TGReaper]

I don't know what make of blower you have but my Buhler/Allied has three shear bolts two are 5/16 (grade 8) that are on the shear plates built into the PTO shaft.
The third one is a 1/4 (grade 5) on the shaft driving the chain,thus protecting the chain and auger.
The reason I mention this is because I wonder if yours has a third lighter shear bolt in a rusted/stuck shear setup.

Dan

 

[leonz]

We have snapped the chain twice on the new blower. The shear bolts are Grade 5 - 5/16" which is recommended. Both times it has been a rock. I wonder it I need softer bolts or a stronger chain. My belief is that the bolt should shear before the chain breaks. The bolts broke the first time the chain broke but not the second time. Any suggestions?

Yowee!!!!!!!

If you are snapping chains your tension MUST be too tight if the little brat is new.

Please forgive the question, but is the shear bolt actually a shear bolt with a weakened end with a cut in the pin?




You should be snapping shear pins not chain period.

The shear pin always always breaks and the roller chain is never a victim unless its old and worn out.


The rule of thumb is that the top flight of chain is taunt and the lower flight is just bit sloppy-about an eigth of an inch of slack as the chain is traveling in one direction only.:thumbsup:

The roller links will have the chain size stamped on the connecting links.


I would call the dealer after you look at the chain tension first as that is my first and foremost thought simply as to much tension will destroy a chain before the sprockets exibit any damage; as it should not snap if the 60H chain is of good SAE quality.

 

[flyingcow]

Might want to bring this up with the dealer.

 

[jake98]

You're SURE you're supposed to use grade 5 shear bolts?

 

[Sumpter]

TGReaper.....The blower is a New Holland spec'd for that tractor. The tractor, blower and everything is brand new so nothing is wore out. I only have about 25 hours on the tractor and less on the implements.

LeonZ and Jake98.....The chain tension is set per the spec in the book and the shear bolt is just a regular 5/16 X 1-1/2 grade 5 bolt that you will find in any hardware store. This is the bolt that the specs call for.

I still need to see what chain I have when I get back home, but if this happens again I will be contacting the dealer to see what I am doing wrong or what my options are. At this time I have made sure I have some master links on the tractor.

The other thought is that I will eventually have all the rocks blown out of my path and won't have to worry about it anymore. :laughing:

 

[SPYDERLK]

TGReaper.....The blower is a New Holland spec'd for that tractor. The tractor, blower and everything is brand new so nothing is wore out. I only have about 25 hours on the tractor and less on the implements.

LeonZ and Jake98.....The chain tension is set per the spec in the book and the shear bolt is just a regular 5/16 X 1-1/2 grade 5 bolt that you will find in any hardware store. This is the bolt that the specs call for.

I still need to see what chain I have when I get back home, but if this happens again I will be contacting the dealer to see what I am doing wrong or what my options are. At this time I have made sure I have some master links on the tractor.

The other thought is that I will eventually have all the rocks blown out of my path and won't have to worry about it anymore. :laughing:

I use 5/16 Gr5 fully threaded bolts. The threads give a shear point.
larry

 

[Sumpter]

I'll see if i can find some of fully threaded bolts and try them out. Good idea.

 

[MF RED in MT]

We have snapped the chain twice on the new blower. The shear bolts are Grade 5 - 5/16" which is recommended. Both times it has been a rock. I wonder it I need softer bolts or a stronger chain. My belief is that the bolt should shear before the chain breaks. The bolts broke the first time the chain broke but not the second time. Any suggestions?

Hey Sumpter, my vote is to go for softer rocks, :laughing:. What I do is pound my snow marker poles (about every ten to fifteen feet of so) into the ground before it snows so I can use them for guides, :thumbsup:. Just a dumb question, but are you at an idle RPM when you engage the snowblower, :confused2:. Hope you figure out your problem, :thumbsup:. KC

 

[Sumpter]

Hey Sumpter, my vote is to go for softer rocks, :laughing:. What I do is pound my snow marker poles (about every ten to fifteen feet of so) into the ground before it snows so I can use them for guides, :thumbsup:. Just a dumb question, but are you at an idle RPM when you engage the snowblower, :confused2:. Hope you figure out your problem, :thumbsup:. KC

Snow marker poles would be nice but not feasable. We plow about 5 miles a road, or I should say old forest service road that someone made into a 5 and 10 acres per lot subdivision years ago. The roads are barely better than primitive. So we have the blower as high as it will go and in float.
I do have the tractor at idle, engage and throttle up. :thumbsup:

 

[MF RED in MT]

Snow marker poles would be nice but not feasable. We plow about 5 miles a road, or I should say old forest service road that someone made into a 5 and 10 acres per lot subdivision years ago. The roads are barely better than primitive. So we have the blower as high as it will go and in float.
I do have the tractor at idle, engage and throttle up. :thumbsup:

Wow, I could only afford the snow markers for a 5 mile road if I placed them every 1/4 mile, but that would not help, . KC

 

[Sumpter]

Once the berms get bigger that will be my snow markers and all will be good here. Supposed to get another foot of snow today. :thumbsup:

 

[SPYDERLK]

I'll see if i can find some of fully threaded bolts and try them out. Good idea.

Buy a little long. Good for any inclusive length.

McMaster-Carr

 

[DemcoEd]

i would be concerned useing that style of bolt. The threads will eventually "cut" the hole and make for a sloppy fit. Once that happens you will be constantantly replacing bolts. Shear pin design protection requires a solid fit/tolerence meaning the bolt has to fit correctly in the hole. Once the whole gets sloppy the poor fit will make it impossible to have the shear pin hold the power it was meant too.

 

[SPYDERLK]

i would be concerned useing that style of bolt. The threads will eventually "cut" the hole and make for a sloppy fit. Once that happens you will be constantantly replacing bolts. Shear pin design protection requires a solid fit/tolerence meaning the bolt has to fit correctly in the hole. Once the whole gets sloppy the poor fit will make it impossible to have the shear pin hold the power it was meant too.

The hole should be harder than the bolt- otherwise the shear would smear the edges of the hole. Nevertheless all shear holes suffer over time. I dont tighten my bolts, leaving them free to turn a little in the hole. I agree. If the thread was always in the same place it would slowly wear threads into the hole.
larry

 

[TGReaper]

We have snapped the chain twice on the new blower. The shear bolts are Grade 5 - 5/16" which is recommended. Both times it has been a rock. I wonder it I need softer bolts or a stronger chain. My belief is that the bolt should shear before the chain breaks. The bolts broke the first time the chain broke but not the second time. Any suggestions?

I am having a real problem with this. I can not imagine a # 60 chain standing up to twin 5/16 shear bolts. There should be another system to protect the chain and auger.
When you find the problem please don't forget to let us know all the details.

Dan

 

[SPYDERLK]

I am having a real problem with this. I can not imagine a # 60 chain standing up to twin 5/16 shear bolts. There should be another system to protect the chain and auger.
When you find the problem please don't forget to let us know all the details.

Dan

It depends on how big the driven sprocket is. -- Anyway, catastrophic overload vanishingly seldom happens simultaneously at both shearpoints.
larry