Outdoor Power Equipment and Small Engines - Shear Pin Replacement

I have an MTD snowflite snow blower that I recently bought 2nd hand, had issues with carb' but figured that out now it's been working fine until day before yesterday when all of a sudden self propulsion system went out, I think it's the shear pin but can't for the life of me find where this darn thing goes, Model No. is 310-600A, anyone have any idea where this pin goes? This may sound like a dumb question but help weathers getting worse by the minute and manually pushing this monster ain't fun. Help!!!!!:wall::wall::wall::wall:

Shear pins are installed in the augers....but a broken shear pin wouldn't cause the drive system to stop functioning. It could be that the drive belt needs adjustment, or it may have broken, or the friction disc might have oil or grease on it.