If Your Snowblower Clogs Too Easily, Check The Shear Pin

If your snowblower seems to be clogging up all the time, rather than curse the gods you may want to check to see if the shear pin snapped off.

This is a part that is designed to break and prevent the device from really being used in case something large that might damage the parts gets sucked up, like a stick or a rock. The shear pin is located on the bar of the auger and your snowblower probably came with a few replacement pins.

A reporter over at Shop Smart, a publishing sibling to Consumerist, learned about shear pins the hard way, in the middle of the big Christmas blizzard. After figuring out the problem and replacing the pin, her previously frustration-inducing snowblower worked smoothly:

That storm came and I awoke to another 18 inches of snow. I bundled up and headed out to start up the snow blower. An hour later I was back inside warming up with a clear driveway and paths. The machine worked like a dream, or maybe just how it is supposed to.

Lessons learned in a snowstorm [Shop Smart]


Edit Your Comment

  1. mcs328 says:

    Is this mentioned somewhere in the user manual?

    • menty666 says:

      usually, but who reads those? :)

      • mike says:

        ALWAYS RTFM!!!

        • jason in boston says:

          First PC I ever built, I read the motherboard manual front to back. No issues on hardware.

          I did the same on every other PC I’ve built for friends/family. No real issues.

          I got some “God lights” for the Jeep for christmas. Read the booklet from front to back for the install. No issues.

          • jason in boston says:

            My point really being, that if you don’t read the manual…how the hell are you going to know how something was supposed to work?

          • GuyGuidoEyesSteveDaveâ„¢ says:

            Are god lights like moose lights the Alaska State Troopers have on their cars.

            • jason in boston says:

              Kinda. My brother is a car guy and said my jeep didn’t look “complete”.


              After reading the instructions and finding a circuit, install took only 30 minutes. The hardest part was drilling the bumper. The electronics were surprisingly easy.

              • GuyGuidoEyesSteveDaveâ„¢ says:

                Yeah, moose lights are a lot bigger than those little things. They are usually around 8 inches around or larger. I saw them on the Alaska State Troopers show on their cars, and DAMN, are they bright and light up the road.

                • jason in boston says:

                  They might not be the biggest lights out there, but they can sure light up a road (or woods). Most definitely not street legal, but when no one else is around, they are amazing. Bright enough to cut through fog and piss off anyone watching a projector.

    • phil says:

      Prominently. I helped a neighbor buy a new snowblower just a month ago: The snowblower came with a pair of extra shear pins attached to the control panel! Yes, it was properly documented in the manual.

      Shear pins (really, who calls them “shearing” pins?) are a common feature on many types of equipment. They save expensive equipment from damage.

      • consumerd says:

        Actually depending on what parking garage you hit here in saint louis certain Amano gates have sheer pins built in them, just in case someone decided to drive through the gate it sheered the pin off and the gate falls down. We sold these pins by the boxfulls for some parking companies.

        Sheer pins are a good thing folks… they get broke saving you money from expensive repairs! and sheer pins are cheap!

        Also reading the owners manual is a good thing too. Especially for computer and broadband equipment.

    • GuyGuidoEyesSteveDaveâ„¢ says:

      Whenever I visit the local lawnmower repair place, they used to be amazed when I brought my manual along because it’s so beat up from me using it to actually troubleshoot/maintain it like it advises me to. They did hate that I usually only showed up to order parts, and not actually bring anything in to fix.

      • PsiCop says:

        So you’re the one who actually R’s the FM, as they say in the tech world … !

        Seriously, I also read manuals. Unfortunately, because so few people do, their quality and completeness have dropped off. Installed a new scanner for a client and had trouble connecting to it on the network. (Following what was in the manual.) Got to the “Troubleshooting” section only to find a reference to the company’s tech support Web site. Aaaaarrrgh! Eventually got it working in spite of the anemic support site and deficient manual.

        • GuyGuidoEyesSteveDaveâ„¢ says:

          One good thing is that the manual has the exploded view of the tractor, and when there’s a problem, I can find the right part number, and usually cross ref it in NAPA’s system to find a cheaper alternative.

  2. gStein_*|bringing starpipe back|* says:

    other solution: move to the south.

    • Evil_Otto would rather pay taxes than make someone else rich says:

      Snow trumps rednecks every day of the week and twice on Sunday. At least for me.

  3. quijote says:

    If your snowblower stops working suddenly, you just stick your hand into the blades and feel around for a while. You’ll get er working eventually.

  4. GuyGuidoEyesSteveDaveâ„¢ says:

    BTW, don’t confuse shear pins with a keystock.

    • phil says:

      True. Though some keystock designs effectively do the same thing in catastrophic situations (sacrifice something cheap and easy to replace in order to save something expensive and hard to replace).

      I once worked a strange ignition timing problem on a single-cylinder lawn tractor engine. The owner had sliced a couple of keys – without damaging the rest of the engine – before we sorted it out…

    • George4478 says:

      Or a Comstock.

      Those things are a Lode to haul around.

  5. kingofmars says:

    Another SNOW news day. Ha, I SLEIGH me!

  6. BorkBorkBork says:

    Be sure to have a few on hand, too. They always seem to go at the worst possible time (when you can’t get out to visit the repair shop).

    • duxup says:

      My Craftsman came with a pair of extra pins. They came nicely mounted on the control panel to make them easy to find when you need them.

  7. npage148 says:

    Just replace them with a grade 5 bolt and you won’t have to worry about replacing them anymore more.

    • TooManyHobbies says:

      Just in case anyone is thinking of trying this, I assume he’s joking. The shear pin is made of soft steel for a reason; if it doesn’t shear, then the transmission or shaft does instead. It’s a safety valve that prevents far more costly damage.

      Just go buy 2 bucks worth of 1/4″ x 2″ bolts and nylon insert nuts, and you’re good for the winter.

      • npage148 says:

        Semi-joking. I’ve had issues where the shear pin won’t hold for normal duty stuff and kept giving out (wet heavy snow). I’ve also done it in a pinch. I also don’t make it a habit of hitting large things while snowthrowing

  8. jjq says:

    If the shear pin snaps, the auger wont spin at all. [or in models with two pins, only HALF will spin] I find it hard to believe that someone would attempt to use a snow blower without realizing the auger was not moving???

    • MyTQuinn says:

      I was thinking the same thing. I guess by “all the time” they mean “every time it comes into contact with snow”.

    • scottcom36 says:

      The auger on a modern snowblower only turns when you hold the lever on the handlebar. Unless you have a mirror in your driveway it’s nearly impossible to watch it turn without an assistant, or you strap the lever down somehow.

  9. TooManyHobbies says:

    When you’ve sheared a shear pin, that’s not called “clogs too easily”, that’s called “doesn’t work at all.”

    And yes, it’s absolutely in the owner’s manual of every blower I’ve used, fairly prominently, in fact.

  10. Beeker26 says:

    And if you live on Long Island, for god’s sake don’t stick your hand in it.

  11. Robert Nagel says:

    Please don’t use a bolt to replace the shear pin. The shear pin will have a grove in it to provide a weak spot for the pin to shear if it is stressed too much. If you use a bolt, and if it shears, it may shear in the wrong place and screw up the shaft and/or connection.

    • sparc says:

      Yep, i was going to mention it myself.

      This is important enough that the article by consumerist should be revised to include the info.

  12. Jay911 says:

    If your snowblower’s auger turns *at all* with the shear pin gone, then something is seriously wrong (bent shaft?) and you should not be using it.

    The concept of the shear pin is that when the auger can no longer turn, it allows the axle to turn freely inside the auger tube. There shouldn’t be enough friction to still turn the auger with no physical connection to the axle.

    • Grabraham says:

      my blower has 4 separate auger sections and four shear pins. if one of the pins goes the other three sections continue to spin and the blower clogs eaiser.

  13. Costner says:

    Most snowblowers (mine included) have two pins on for each side of the main auger. It is quite common to shear one and not the other and unless there is a significant amount of snow you may not even realize it since the second stage of the snowblower will still throw the snow just fine.

    In a pinch I used one of those cheap wire “u” shaped landscape stakes – the kind you use to hold plastic or weed mat down. I just stuck it in and bent one end around the shaft. It worked just fine and was obviously a small enough diameter that it would shear off long before any damage.

    When it came time to replace it permanently, I found Sears had a type which just slips in and has a hoop to connect to the other end. No tools required – so I bought a few extra and keep them at home just in case.

    • Nighthawke says:

      That’s a Cotter Pin, and is completely different than the shear pin that is designed to do that job. It’s low tech and may hold, but get some shear pins before you lose your drive shaft or worse.

      • sean says:

        No, the OP has it right. The shear bolt is secured by a clip that is drilled into the bolt head and swings over the base to secure it. It’s the correct factory part for Craftsman snowblowers. It’s not a cotter pin at all.

      • Costner says:

        I’m not an idiot – it is not a cotter pin and the packaging specifically stated “shear pin” and was found with the other snowblower parts.

  14. SkreanAme says:

    The scary part is that it still works at all with a sheared shear pin.

  15. JonBoy470 says:

    Wow, and here I was thinking that knowledge of shear pins was universal amongst snowblower owners…

  16. FrankReality says:

    Just to add to the discussion, some snowblowers use shear pins, some use shear bolts.

    Shear bolts come in various sizes and strengths – it is important to get equivalent to OEM shear bolts. I’ve seen then in soft steel, brass and aluminum.

    Shear pins are typically rolled metal and are friction fit.

    And yes, be prepared – have a supply on hand. You really don’t want to substitute a regular bolt.

  17. Segador says:

    This may be the most oddly specific Consumerist post ever.

  18. Chip Skylark of Space says:

    A nice rule of thumb is that if you need to replace your shear pin(s), buy extras. If they break once, they’ll break again, and you’ll be in the middle of a storm when they do. Most blowers have a pin on each side, so buy 2 or 4 of them at a time, even if you only need 1 right now.