Shear pin nightmare

[Bigbear4x4]

I would be forever grateful if someone can solve this problem I have.
I have an older Erskine Rear PTO snowblower. I refurbished and painted it to kinda match my 4115 John Deere.
Problem is I can snowblower all afternoon no problem. If I turn off the PTO for 2 - 3 minutes then back on , starts up great.when I stop the blower for 5 minutes or so while cleaning up with the bucket. When I turn the blower back on , SNAP , there goes another driveshaft shear cut bolt. The unit is garaged at 56 °f
So now , obviously, everything is locked up tight. I return to the garage and an hour or 2 later go examine it and find No rocks and now everything spins freely with no sounds of rubbing anywhere. There are drain holes behind the impeller.
I bought this from my brother who run it 3 years and never cut a shear pin ! What's happening ?

 

[airbiscuit]

You need to check it right after the shear pin breaks (not after it has thawed out) to see what is blocking it. One theory is that maybe you aren't giving it a chance to clear out fully when you stop blowing and then it gets stuck on a chunk of ice.

 

[Bigbear4x4]

You need to check it right after the shear pin breaks (not after it has thawed out) to see what is blocking it. One theory is that maybe you aren't giving it a chance to clear out fully when you stop blowing and then it gets stuck on a chunk of ice.

Your right, Hard to get around with an oxygen tank hanging from my neck because I have COPD. Thanks for your quick response.

 

[zzvyb6]

Leave it parked outside. Its the warm garage melting some schmutz of the chute, falls into the cold impeller, maybe refreezes, and locks it up.

 

[airbiscuit]

Another option is to raise the blower a bit and keep the PTO on while you're doing your bucket work.

 

[CalG]

Are those "electro-matic" pto clutches to blame?

(I don't know if your tractor has such)

Inertia is a LAW!

 

[seville009]

Two possible issues:

1. Shear pins you are using may be the wrong grade (too weak). Check the manual to see what grade they shoukd be.

2. The slight moisture that builds up around the fan that shoots the snow up through the chute while it’s running (melting particles of snow due to friction ) can freeze up quickly when you stop for a minute while you’re snowblowing. That happens to the blower on my skidsteer (which is all hydraulic; no shear pins). I carry a small ten pound hammer in the cab and give the fan blades a few quick heavy whacks to break the ice bond. It works.

My guess your main issue is the quick freeze up described in #2 since it only happens when you engage the pto after having run it for awhile. Keep a hammer under your seat and give the fans blades some strong whacks; it won’t hurt them.

 

[Bigbear4x4]

Thanks guys for your input but keep in mind, my brother run it three years on the back of his Ford tractor and Not once did he ever snap a shear pin. All I did to it after I bought it was clean it up and paint it.

 

[Dave M7040]

I can understand your breathing challenges and commend you for continuing to try and get chores done. My wife of 54 years had lung issues and died this past Aug.

Could you please post a photo of the head of the bolts you are using as shear bolts.
A closeup photo of the shear bolt hole. Has it become oval with the frequent shear bolt breaking.
A photo of the blower in the fully raised position so we can judge the angle the U joints are having to deal with. I am assuming when you restart the blower it is in the fully raised position.

In the short term keep the blower running during the times you are using the bucket.

Looking forward to your reply.

Dave M7040

 

[jfsawatzky]

My thought is something is freezing once you stop long enough for it to freeze. If your stop is short enough it does not have a chance to refreeze. When you park it inside again it has a chance to thaw out again.
Does the type of snow or temperature make any difference to breaking shear pins?

 

[groundcover]

Only thing different is the paint, those John Deere colors are the problem !
grade two bolts will work as shear pins. I agree with the ice problem, keep it spinning until you get back to the heat.

 

[seville009]

FWIW, I didn’t have a problem with the fan freezing up on me until probably 7 or 8 years after I had it.

It’s possible that, over time, either because of the original paint wearing off, or maybe a slight change in tolerances, the freezing up of the fan just starts happening. Who kniws….things change over time.

 

[ruffdog]

Thanks guys for your input but keep in mind, my brother run it three years on the back of his Ford tractor and Not once did he ever snap a shear pin. All I did to it after I bought it was clean it up and paint it.

With the Ford, you can ramp it slowly up to speed. Does your Deere have an electric PTO clutch? Do you drop the RPMs down before engaging the PTO? Does the blower rotate easily by hand (tractor off) ?

 

[Bigbear4x4]

With the Ford, you can ramp it slowly up to speed. Does your Deere have an electric PTO clutch? Do you drop the RPMs down before engaging the PTO? Does the blower rotate easily by hand (tractor off) ?

I Always lower rpm to about 1500 and lower blower to the group. Once it starts working , I bring it up to 2500 rpm. Right now, thawed out, every in neutral spins very nice. No rubbing anywhere. And yes , electric pto. Thanks for your input

 

[Bigbear4x4]

FWIW, I didn’t have a problem with the fan freezing up on me until probably 7 or 8 years after I had it.

It’s possible that, over time, either because of the original paint wearing off, or maybe a slight change in tolerances, the freezing up of the fan just starts happening. Who kniws….things change over time.

Ha ! Age goes hand in hand with unexpected surprises and they're usually not very nice!

 

[Bigbear4x4]

Only thing different is the paint, those John Deere colors are the problem !
grade two bolts will work as shear pins. I agree with the ice problem, keep it spinning until you get back to the heat.

Guess I created more work for myself. Tried to make it look respectable and this is what I get ! Lol. Started with Mardens soft bolts no grade, probably made in China and worked my way up to grade 3 .
Guess I will have to let her spin !
Before & After pix

 

[Bigbear4x4]

My thought is something is freezing once you stop long enough for it to freeze. If your stop is short enough it does not have a chance to refreeze. When you park it inside again it has a chance to thaw out again.
Does the type of snow or temperature make any difference to breaking shear pins?

I agree but why this freezing issue now but was fine past 3 years. He didn't do anything differently.

 

[stuckmotor]

When the title mentioned a shear pin nightmare. I thought it would be on a snowblower. Those machines must eat pins for breakfast. Good luck with it.

 

[oosik]

When you shut it down to use the bucket - water/slush refreezes - - somewhere. Don't shut it down. Does not hurt a thing to keep it running.

I use to have a 3-point blower. Any time I had to blow anything less than dry, fluffy snow - I could have the same experience. Just about anything would blow a shear pin on mine. Ice chunk, frozen slush, limb, stick, frozen pocket gopher - you get the idea.

Going to a higher grade shear pin IS NOT the answer.

 

[Bigbear4x4]

I can understand your breathing challenges and commend you for continuing to try and get chores done. My wife of 54 years had lung issues and died this past Aug.

Could you please post a photo of the head of the bolts you are using as shear bolts.
A closeup photo of the shear bolt hole. Has it become oval with the frequent shear bolt breaking.
A photo of the blower in the fully raised position so we can judge the angle the U joints are having to deal with. I am assuming when you restart the blower it is in the fully raised position.

In the short term keep the blower running during the times you are using the bucket.

Looking forward to your reply.

Dave M7040

Hi, using grade 3 bolts, no oval to bolt holes, gotta tap em in gently with a hammer. I never turn on in raised position and always drop rpm to almost idle

54 years together must have been devastating! I would like to offer my condolences.
Thank you for sharing your knowledge..