Snowblower Snowblower Issues

[scesnick]

Hello,

I have a Ber Vac 64" 3pt. blower hooked up to Yanmar 2000BD and it works O.K. but I can't seem to get it to quit breaking sfeer pins. I use a normal bolt ( grade 5 ) with a nut on the other end.

Not sure how other blowers work but the Ber Vac blower has a shaft that runs the fan and then another shaft runs straight from the center of the fan to the auger, The sheer pin goes right where these to shaft come together. I was wondering if I was to drill the sheer pin hole out to accomodate a little bit bigger sheer bolt, would I have less pin breakage? Any other ideas are welcomed....

 

[dqdave1]

your shear bolt hole may have oblonged out of round, causing movement in the shear pin, which will cause premature shear pin breakage. You could drill it out to the next size and not create any major problems.

 

[hwp]

Shear pins are there to protect your equipment. A bigger bolt reduces the protection of your equipment. How big a bolt are you using? If it is 5/16" or more then it should be big enough for your unit, especially since your are using grade 5 bolts. I'd suggest you look to see if there is a reason why so many bolts are breaking. It sounds like something is trying to stop the auger from turning. You should be able to turn the auger by hand. Is there a gearbox at the end of shaft #2? could it be binding? seized? etc.? Or possibly a bearing at one end of the auger is seized?

 

[scesnick]

Thanks for the replies.

No, my fan and auger move nice and easy by hand. The pin is not very big at all. I think It may be oblonged like dqdave suggested. I don't think the bolt is anywhere near 5/16. I always thought it was a tad small for the size of the blower. I gues I will drill it out to a little bigger size. Thanks...

 

[George2615]

My blower uses Grade 5 1/4" bolts with a regular nut. I usually shear 2 or 3 each time I use it. That is mainly because the driveways I use it on are gravel. It doesn't take much of a rock or chuck of hard ice to get jammed in there and shear a pin. I just keep a handful of spares in my toolbox. Takes me about a minute to change one. Another thing that shears mine instantly is engaging the PTO at full PTO speed so I ease out on the clutch to slowly bring it up to speed. I'd rather shear a pin than damage something else. You can also check with the blower Mfg. some blowers do use a grade 8 bolt instead of a 5.

 

[WayneB]

I have a woods ss-60 and shear bolt is right at the shaft connection the PTO on the tractor. Mine uses a 5/16" x 1" grade 8 bolt. I have put a 3/16" bolt in (by mistake) and it lasted about 35 seconds. Couldn't believe my stupidity, but with the proper bolt it had not sheared yet!

Someone had mentioned using a 5/16” class 5 bolt as they felt the class 8 bolt might be too strong for the application. I contacted my Kubota dealer and he told me it should be a class 8 bolt so I went ahead and used them. I think you should contact the blower manufacturer and see what they recommend to do. I would worry more about damage to the tractor PTO section than the snowblower.

 

[diyDave]

The way to keep from breaking shear pins is to keep them tight. Use a stover locknut, or a nylon insert locknut from the start, and your bolt won't get loose enough to start egging out the hole.