bearing 62 and extends beneath the housing 60 an outer end 38a of the shaft 38 has a stub shaft 64 nonrotatably fixed thereto the stub shaft 64 has a slot therein which receives the outer end 38a of the main shaft 38 aligned openings in the stub shaft 64 and the outer end 38a receive a bolt 65 which secures the members 38 and 64 together an annular groove 66 is provided on the stub shaft 64 an auxiliary shaft 67 is journalled at the top and bottom by bearings 68 and 69 and terminates at an outer end 70 the stub shaft 64 may be alternatively mounted on the outer end 70 of the auxiliary shaft 67 the combination secured together by the bolt 65 the auger bit 40 includes an end portion 71 having an opening 71a which receives the stub shaft 64 therein a bolt 74 passes through aligned openings in the bit 40 and the stub shaft 64 to mount the auger bit 40 on the auger 10 an auxiliary bolt not shown passes through the bit 40 to engage the groove 66 of the stub shaft 64 and provides a back up means of securing the bit 40 to the stub shaft 64 nonrotatably mounted on the coupler 37 as by welding are a set of sprockets 37a and 37b mounted on the auxiliary shaft 67 by a bolt 67a is a coupler 72 having a set of sprockets 72a and 72b in fig2 and 3 endless chain 73 is mounted on respective sprockets 37a 37b the housing 60 encloses.