Here’s a photo showing where they typically go. The main auger ‘axle’ is actually a hollow tube with a shaft turning inside of it. The shear bolts go thru holes that line up in both so that the shaft inside turns the auger tube (and the blades). If you hit something with the auger the shear pins are ‘the weakest link’ and will break (or ‘shear off’) to prevent any other drive line component from being damaged. You’ll know if you’ve broken them if the auger will not spin when engaged.
