Why Do I Keep Breaking the Shear Pins On My Snowblower?

Why are my shear pins breaking on my snowblower?

The reason you keep breaking the shear pins on your snowblower is because there is a foreign object in the snowblower, wrong shear pins, or wrong blade bolts. Too much work on the auger can also be a reason your shear pin keeps breaking on your snowblower.


snowblower breaking pins


Wrong shear pins

The shear pin for your snowblower must be of the appropriate size. Using the wrong shear pin will keep breaking the pins on your snowblower. This happens because it’s either too loose or tight.

There are several shear pin types, sizes, and lengths. Here is why you must ensure you choose the right size for your snowblower. You will require a shear pin that can break at the appropriate amount of torque.

You risk damaging your snowblower severely if you use a pin with a higher torque capacity than your machine. Make sure that when you replace your pins, you use the exact replacements that are called for in the owner’s manual. To determine the appropriate component number for your device, see the service parts section of the owner’s manual that came with it.


Presence of foreign object

Shear pins not only prevent the gears and gear case from being damaged, but they also serve a vital purpose in terms of safety. If a foreign object becomes lodged between the housing and the drills, the gears inside the case will begin to bind and wear. When this occurs, the auger shaft and gears cannot continue freely spinning.

If the jammed object is not removed, it will eventually cause considerable damage to the gear case if allowed to continue.

Before using your snow blower, it is important to search the surrounding area for large things that are not native to it. Quickly remove those objects from the path you will be working on. Buying extra shear pins before the season starts will ensure that you always have a spare on hand if any of them break, reducing the amount of time your snow blower is out of commission.


Too much work on the auger

Snowblowers can move many tons of snow in an hour. The augers on the snowblower make it easier to break through ice and snow-packed down. On the other hand, a shear pin could break if the strain is too heavy for the augers to manage successfully.

A shear pin is a type of safety mechanism designed to fail if the torque on the augers is increased to an unsafe level. If you do this, the auger’s driveshaft will remain intact even if it runs over a curb, a newspaper, or a rock hiding in the ground.


How to fix a snowblower that keeps breaking the shear pins?

You can fix your snowblower that keeps breaking the shear pin by replacing the spark plug, lubricating the drive and chassis, and adjusting the ground pressure. Another way to fix your snowblower that keeps breaking the shear pin is by replacing the pin with the correct size.


  • Before storing the snowblower, always run the blower on a clear surface to clear the auger of any remaining snow and clear the area around the throw chute and the housing of snow.
  • After each use, make sure all screws and bolts are snugs.
  • Look for broken or worn pieces and replace them right away.


Replacing the spark plug

When you replace the spark plug, your snowblower will likely break its pin because this will stop the machine from running rough and reduce the chance of a breaking pin. Note: check the owner’s manual to ensure you have a suitable replacement. Here are steps to fix it;

  1. To replace the spark plug, first, disconnect the lead fire
  2. Use a socket wrench to remove the old spark plug and discard it
  3. Replace it with a new plug and be careful not to over-tighten it
  4. Lastly, reconnect the lead wire.


Lubricate the drive and chassis

Lubricating your snowblower’s drive and chassis prevent the machine from clogging or attracting foreign objects and stopping the pin from breaking. Here are steps to fix;

  1. Disconnect the spark plug wire and ground it against the engine
  2. Run the engine until it is out of fuel or use a siphon pump to remove the fuel
  3. To access all the parts, tip the snow blower on its side if possible.
  4. Remove the lower frame cover from the underside of the snowblower
  5. Using a soft cloth, apply a little engine on the hex shaft. If you are using any spray, carefully spray the drive and avoid any contact with the aluminum drive plate.

Notes: You should only lubricate at least once a season or after every 25hours of operation.


Adjust the ground pressure

The deck must have the proper ground pressure to prevent the shear pin from breaking. Here are steps to fix it;

  1. The first step is to check the tie’s air pressure. 8.5 PSI
  2. Put the rider on a level surface
  3. Put the lifting lever in the mowing position
  4. Gauge the feet between the ground and the front and back of the cutting unit hood.
  5. Ensure the cutting unit slopes forward slightly so that the rear edge is 2-4mm higher than the front edge.


Replace the pin with the right size

Replacing your shear pin with the correct size will prevent your snowblower from further breaking your shear pin. Here are steps to fix it;

  1. Detach the spark plug cover.
  2. Lift the snow blower housing off the ground and support it with a wood block.
  3. To determine the proper size shear pin to use as a replacement, consult the owner’s manual. you can purchase replacement shear pins at any hardware shop.
  4. Put the new shear pins in the holes where the old ones used to be. Using a socket wrench, set each shear pin in place, then tighten its nut. The snow blower can now be started by reconnecting the spark plug. Ensure that the driveshaft and the auger shaft rotate by engaging the augers.


Why do I keep breaking shear bolts on my snowblower?

The reason you keep breaking shear bolts on your snowblower is because of too much load on the blower, lack of lubrication or you have a weak shear bolt. Your auger or impeller hitting a strange thing can be another reason your shear bolts keep breaking on your snowblower.

Your snow blower’s shear bolt is responsible for securing your augers to the auger shaft. However, if an obstacle clogs and stops your augers, the shear bolt will break to protect your auger gearcase. Here are ways to fix your broken shear bolts:

  1. Put the snowblower down on a firm ground that is level.
  2. After turning off the switch that controls the engine, remove the cap from the spark plug.
  3. Clear the snow, ice, and other foreign objects from the auger and the blower.
  4. Examine the entirety of the snow removal system.
  5. Find the appropriate new shear bolts.
  6. Carefully take out the old and broken shear bolt.
  7. Use the replacement shear bolt to extricate the old broken bolt from the shaft. It will fall out immediately.
  8. After removing and installing the old bolt, apply a nut to the new one.
  9. Make the nut and bolt more secure by turning them with two wrenches measuring 7/16 inches.
  10. Do not over tighten
  11. To your great satisfaction, both of the shear bolts have been replaced.
  12. When purchasing additional items, ensure you get a lot of shear bolts.


Why do I keep breaking cub cadet shear pins on my snowblower?

The reason you keep breaking your cub cadet shear pins on your snowblower is because of a hard particle presence or your augur’s malfunctioning. Below is how to fix your broken cub cadet shear pins on your snowblower:

  1. Ensure the engine has cooled down completely before attempting to repair the cub cadet shear pin on your snow blower.
  2. The next step to prevent the engine from being started inadvertently is to remove the wire and boot from the spark plug.
  3. I strongly suggest you carry out this treatment with very little petrol, if any, in the tank.
  4. Carefully reverse the direction of the snow thrower so that the handles support it.
  5. Rotate the suitable auger blade so that the shaft holes are aligned, and then use a punch and a hammer to smash out any fragments of the old broken cub cadet shear pin.
  6. Insert the new shear pin into the shaft holes and then use the retaining clip to lock it in place. This completes the installation of the new shear pin.
  7. Bring the snow thrower back up to its upright position.
  8. Reattach the wire to the spark plug and fill the fuel tank after you’ve finished. And at this point, your snow blower ought to be prepared for usage.


Are snowblower shear pins universal?

Snowblower shear pins are not universal and are in three standard sizes.

  • Smaller, entry-level snow blowers typically employ brass 1/4″ shear bolts.
  • Larger mid-tier snow throwers should use the black 5/16″ shear bolts.
  • The most long-lasting shear bolts are silver 5/16″ ones, which you’ll find on commercial snow blowers.

Note: Choosing the right one is crucial to the smooth operation of your snow thrower. If you have shear pins, you can replace the pins in a matter of seconds without having to risk going to a hardware store. It’s a good idea to keep extra shear pins on hand if your snow blower breaks down in the middle of a snowfall.


How long should snowblower shear pins last?

Snowblower shear pins can last for a year or two. However, a friend said his ST 8-24 pin lasted 12 years. So, in my opinion, how long a snowblower last depends on the manufacturer and how you use it.

Ensure you practice the following to make your pin last longer:

  • Installing a wicket gate monitoring system
  • Add a compressed air system to detect shear pin failure