We have had a lot of Snowblowers coming in with striped gears in the front auger gear box due to the use of hardware bolts and not shear pins. Or lack of liberation on the shaft that the augers ride on and they are rusting together. This is a very expensive repair.
Two-stage snowblower impellers and augers are partially held in place by little bolts called shear pins. These pins are actually designed to break under the strain of a specific level of torque, such as when something jams up the turning auger blades.
When a snowblower shear pin breaks because of some obstruction in the working end of the machine, the auger blades stop turning and the much more expensive engine gears are saved from demolishing themselves under their own power.
Most two-stage snowblower owners will experience a shear pin break in the course of their machine’s life.
It is extremely important that snowblower shear pins be replaced with Original Equipment Manufacturer (O.E.M.) parts. These pins must be perfectly engineered to match the torque breaking level specific to each snowblower in order to work correctly.
If the pins are too brittle, then they will just keep breaking in low stress situations over and over. If the pins are too durable, then they put the snowblower’s gears at risk by failing to break when they are most needed.