snapped chain.....twice

[Sumpter]

I will be going by the NH dealer on Thursday so will stop and see what they have to say about it. The one shear bolt is about six inches from the gear box, then the shaft goes to the chain, then chain to the auger sprocket. Seems like there could have been a shear on the auger itself but there isn't. The second is on the 2nd stage.

 

[Sumpter]

Okay I am about to give up. Snapped the chain twice again. Once yesterday and again today. I have the 60H on already and the bolts just won't shear for some reason. It has the right bolts. I now have 5 master links in the chain. I did get a new chain so might change it out. Just don't understand this problem.

 

[flyingcow]

It just seems to me that it's a problem the dealer either needs to fix, or more likely, needs to replace the whole unit? they'll need to try it out. Ask for a "loaner"?

My blowers(rear mount) have had a shear bolt on the PTO and a second on the shaft, just before sprocket that drives the augers. only time i shear a pin, is when i engage the pto while anything above a low idle.

 

[crazyal]

I think you should go to the dealer as well. If you aren't ready to I would remove the auger shear bolt and try to blow snow without it. I've never tried it but on my blower I don't even think the auger would turn even without snow.

Maybe the sprockets aren't inline and you're not breaking the chain from force but are twisting it loosening up the plates and weakening the chain?

 

[Jackfr]

I was breaking chains on our 8' blower. I replaced the chain and got some grade 2 bolts from True Value to replace the shear bolts (one 1/4" bolt on the sprocket and two 5/16" bolts on the drive shaft). The bolts shear way before any damage to the chain or sprocket. If you don't over work the blower they last quite awhile but I carry extras in the tractor with wrenches with me. It's a lot quicker and cheaper to replace these cheap bolts than other parts of the blower.

 

[wedge40]

Have you removed the shear bolts? How tight are the nuts? I would look at getting a replacement chain.

Wedge

 

[etcallhome]

After talking to dealer about this problem ,If they don't talk to manufacture about this problem , I would call and find out if they have had any problems.
Could just be the chain ,, I read where you had a new one just not put on .
Grade 5 all thread will break a lot quicker than the others.. Last winter I went through 15-20 all threaded.. changed to just threaded on end of bolt maybe 4 rest of winter and this year total..
Good Luck

 

[kevinj]

I would like to see some pics of the drive line, shear points etc.

Also where is the rock wedging?? In the augers or impeller.

Some shear bolts MUST be left slightly loose to work properly.

On my Kubota (Rad) the impeller bolt cannot be tight or the two flanges clamped together add to the shear. If slightly loos the bolt is the only shear point.

 

[Jay4200]

Okay I am about to give up. Snapped the chain twice again. Once yesterday and again today. I have the 60H on already and the bolts just won't shear for some reason. It has the right bolts. I now have 5 master links in the chain. I did get a new chain so might change it out. Just don't understand this problem.

You either have a defective chain, your tensioner is improperly adjusted, or something is misaligned in the chain drive. The chain should be snugged up with the tensioner - if you leave slack in the chain, it will cause it to prematurely snap. If your chain is snug when adjusted, I would take it back to the dealer for a chain drive inspection and at the very least demand a new chain.

My 6' blower has two shear bolts - one standard 5/16" snowblower shear bolt on the PTO shaft, and one 1/4" grade 5 bolt on the shaft between the transmission and first chain drive gear. I got the blower packed full of cement-like snow two weeks ago - I tried turning the blower over (at idle) before it was fully cleared and immediately broke the PTO shear bolt.

My blower is a 25-40HP rated blower, but snapping at idle tells me that the shear bolts will break with WAY less than the 37HP that my tractor PTO can produce. A healthy #60 drive chain can certainly handle 40HP (I run similar HP through smaller chains on my dirtbikes all the time).

JayC

 

[flyingcow]

I would like to see some pics of the drive line, shear points etc.

Also where is the rock wedging?? In the augers or impeller.

Some shear bolts MUST be left slightly loose to work properly.

On my Kubota (Rad) the impeller bolt cannot be tight or the two flanges clamped together add to the shear. If slightly loos the bolt is the only shear point.

Don't know much, but i've never left a shear bolt"loose" to work properly. You will oblong the holes the bolts are in. Makes no sense to me. But, what do i know? been snowblowing for 15yrs.

Explain "loose"