# Pto shaft , snowblower



## Tom Caroselli (Aug 10, 2017)

I have a lucknow 60" snowblower. I've been breaking shear bolts on the pto that's hooks to the tractor, I've been using grade 8 bolts per lucknows techs advice. I think what is happening is the bolt gets loose then it breaks. I tightened it up as tight as possible. What can I do to prevent this.? Thank you in advance.


----------



## pogobill (Jan 31, 2012)

I'd make sure the bolt was a snug fit, and maybe use a locknut.
I also idle my tractor down and engage the PTO slowly to avoid the pins shearing. Also make sure your blower is clear of snow when you are done blowing. It can cause an excessive load on the blower at startup, or even freeze and jam the impeller.


----------



## Tom Caroselli (Aug 10, 2017)

pogobill said:


> I'd make sure the bolt was a snug fit, and maybe use a locknut.
> I also idle my tractor down and engage the PTO slowly to avoid the pins shearing. Also make sure your blower is clear of snow when you are done blowing. It can cause an excessive load on the blower at startup, or even freeze and jam the impeller.


Done everything you said,I used a lock nut. Might need a new pto shaft.


----------



## pogobill (Jan 31, 2012)

Well, do you think that maybe you are a little aggressive when blowing snow? If you push to hard into the snow, it could put too much strain on the components. If you are blowing snow and leaving a considerable windrow of snow, you are going too fast.


----------



## deerhide (Oct 20, 2016)

Shear bolts are 'made to break'. They are supposed to be the part that breaks first in the event of an overload by a foreign object or too much hard snow. Grade 8 seems awful hard for a shear bolt, a Gr. 5 would be as hard as I would use and yes, a loose shear bolt will break sooner than a tight one. Are you running your pto at 540 rpm or even a little more?


----------



## pogobill (Jan 31, 2012)

The only time I bust a shear pin is if I pick up a rock or chunk of ice the jams the impeller, or I find that darn piece of 2 x 4 that I meant to pick up before the first snow fall!


----------



## Groo (Jan 17, 2020)

maybe the wrong g size bolt? might try drilling it out to the next size to make sure it's a snug fit.

Dad wanted to use grade 8 bolts for his brush hog. I told him it might not be the mower that breaks.
he was using the wrong size.


----------

