Shear pins are a safety feature on your snow blower, designed to break under stress to protect the auger and gearbox. However, over time, they can seize due to rust or corrosion, making removal a challenge. Don’t worry—here’s a step-by-step guide to safely remove a seized shear pin, including how to drill it out if necessary.
What You May Need
Penetrating oil - Something stronger than WD-40
Hammer and punch
Heat source (propane torch or heat gun)
Pliers or vice grips
Drill and metal drill bits
Safety gear (gloves, safety glasses, and hearing protection)
Step 1: Inspect and Clean the Area
Clean the area around the seized shear pin to remove dirt, ice, or debris. This will improve access and help you assess the situation.
Step 2: Apply Penetrating Oil
Spray penetrating oil on both sides of the shear pin and let it soak for at least 15–20 minutes. This helps to loosen rust and corrosion. For severely stuck pins, apply oil multiple times over a few hours.
Step 3: Tap the Pin Loose
Use a hammer and punch to gently tap the pin, aiming to break the rust bond. Start with light taps to avoid damaging the auger or shaft. If the pin moves even slightly, continue tapping to work it free.
Step 4: Use Heat for Stubborn Pins
If the pin doesn’t budge, apply heat to the area using a propane torch or heat gun. The heat will cause the metal around the pin to expand slightly, making it easier to remove. Be cautious to avoid overheating or damaging nearby plastic parts.
Step 5: Twist and Pull with Pliers
Once the pin is loosened, grip it with pliers or vice grips. Twist gently while pulling the pin out. If it resists, alternate between twisting and tapping it further with the hammer and punch.
Step 6: Drill Out the Pin (If Necessary)
If the pin is completely seized and other methods fail, drilling it out may be the best solution. Follow these steps:
Select a drill bit slightly smaller than the diameter of the pin.
Drill straight through the center of the pin.
If necessary, start with a smaller bit and work your way up to avoid damaging the surrounding metal.
After drilling, use a punch to drive out any remaining fragments of the pin.
Step 7: Clean and Prep the Pin Hole
After removing the pin, clean the pinhole with a wire brush or sandpaper to remove rust and debris. Apply a light coat of grease or anti-seize compound before inserting the new pin to prevent future seizing.
Step 8: Install a New Shear Pin
Replace the old pin with a new one that matches the manufacturer’s specifications. Secure it properly, but avoid overtightening—it’s designed to break under stress.
Prevention Tips
Regularly inspect and replace shear pins as needed.
Apply anti-seize compound during installation and a few times a season to prevent future corrosion.
Store your snow blower in a dry area to minimize rust.
Removing a seized shear pin can be time-consuming, but with the right approach, you can get the job done. Whether you need new shear pins, penetrating oil, or someone to tackle the job for you, Cumberland Power Equipment has you covered. Visit us today for expert advice and all the supplies you need to keep your snow blower running smoothly!
