You’re halfway finished snow blowing your driveway in a snowstorm and clunk...you hit a rock (or something even worse). Now, your thrower's engine is still running at full speed, but the auger is jammed.
The good news is your machine was designed to handle this situation. The bad news is; you’re going to need to replace a shear pin or two.
What is a Shear Pin?
Typically, two shear pins (shear bolts) connect the auger to the auger shaft. They feature specially designed grooves, allowing them to snap if there’s too much torque. This prevents damage to the gear case and auger shaft.
If two-stage snow blowers weren’t built with shear pins, a snow-covered newspaper or a curb could cause hundreds of dollars in damage instead of a few bucks.
How to Replace a Shear Pin
Replacing a shear pin is very easy and only takes seconds to do.
Never stick your hands inside the auger housing until the snowblower engine is safely turned off. To locate the bolts, look for where they intersect through the auger shaft.
Use wrenches to loosen the bolt. Make sure they fit the size of the shear pin. Hold the nut in place on one side while using another wrench to turn the bolt counter-clockwise until it's loose enough to turn with your fingers.
Remove the bolt. If the shear pin is already completely broken, simply pull the pin out from both sides of the auger and stick the new one in its place.
Insert the new shear bolt. Make sure the holes are aligned and tighten the nut.
How to Size a Shear Pin
There are three basic sizes of shear bolts, and it's important to select the correct one for your snowblower to ensure it fits and works correctly.
Brass 1/4" shear bolts are most commonly used on smaller, entry-level snowblowers.
Black 5/16" shear bolts are for larger mid-grade snowblowers.
Silver 5/16" shear bolts are the most durable and are used on professional-grade snowblowers.
It's a smart investment to always have a few extra shear bolts on hand in case something happens when you're snow blowing, especially during a snowstorm. Remember the reason you have a snowblower in the first place is so you don't have to shovel.
Not only will having shear bolts save you a dangerous trip to the hardware store, but you'll only spend a few seconds replacing them and be back to blowing in minutes.