Have a Mastercraft snowblower 8-26. Shear pin broken , where in machine do I find pin to replace?

You have to rotate the blades by hand and look in the hole that the shear pin goes in. ( the shear pin drives the blades and is designed to "shear" off if something gets caught in the auger. usually there are two of them through the center shaft of the blades that chew up the snow) The body of the old shear pin will still be in the center, it will look like a fine line in the shape of a circle. you will need to take a punch and drive the old shear pin out , and replace.