bison88

I have an older toro 3521 that was in great shape until now.chewed up some rocks mixed in with snow (dang snowplow).will not throw snow under load .auger can move by hand .I replaced belt but still not throwing. cannot find sheer pins or bolts on toro parts viewer does any one know where they are or are they called by another name .I would like to replace them first before tryig to dis assemble worm gear

                                                                                 thanks RS