Why break chain on snowblower?

[dutchman56]

When blowing snow on the road to my camp I am breaking main auger drive chain instead of shear bolts. Any others is this a problem. I have a GL4630gstc with 72" front mount blower. I was expecting to pick up some rocks the first couple blows but first time broke chain and shear bolt and second time just chain.

 

[ccsial]

It would seem the chain is weaker than the shear bolt. I'd try getting a lower grade shear bolt. I don't understand why they put an ungaurded chain on the blowers anyway. Seems like an accident waiting to happen.

 

[hayden]

In the snow blowers I've seen there are two sheer bolts. One is part of the main drive line coming from the tractor to the snow blower and protects the drive shaft and gear box. The second is on the secondary drive shaft that runs from the gear box to the auger drive chain. This one protects the auger, drive chain, and secondary drive shaft.

If the chain is breaking, the chain might be weakened and/or the sheer bolt is too strong (too high a grade). On my first snow blower I was breaking chain links and finally took a closer look at it and discovered that essentially all the link straps had fracture lines in them. They were all ready to break. I don't know whether this was caused by some shock load the first time it broke or some other fatigue. After replacing the chain I never had another problem.

As for the sheet bolts, check the owners manual to see what's called for.

 

[dutchman56]

The book says 5/16 x 1 3/4 grade 5. Seems hard to me but the chain is 60hd so you would think it could handle it. the second shear bolt is right at the front of second stage impellar and no problem with it sofar but no chain involed with that one.

 

[art]

If you think of the conditions that snow blowers work under the rust is a rear problem on enclosed shafts. I'd recommend checking both shear bolt locations or three spots. Remove the shear bolt and make sure both halves turn freely and seperately.

 

[hamsey]

Check the shear bolts and see if they have machined grooves in the smooth section. They are not just plain Jane grade 5 bolts.

Norm

 

[ccsial]

Check the shear bolts and see if they have machined grooves in the smooth section. They are not just plain Jane grade 5 bolts.

Norm

This is correct. Mine are this way too.

 

[dutchman56]

I thought they would be like on walkbehind blowers. But the orginal bolt with orange paint had no groove.

 

[rpraymond]

Did you lower the skids on your blower and do you set the hydraulics to float when you blow snow? I use a front mounted blower on a gravel driveway and until a layer of hard packed snow builds up this technique works well. Also TSC has a selection of shear bolts that might help solve the problem. One more thought, is the chain tension adjusted properly? A slack chain can break prematurely.
Good luck.

 

[dutchman56]

Have skids set as high as possible and chain is the 1/2" play as spec'd. May look for grooved bolts, but will check with dealer first