Abstract: Speed reducer, such as a screw conveyor drive, adapted to receive a shaft within a tapered sleeve. The shaft includes a tapered portion adapted for engagement with the corresponding tapered portion of the sleeve on one side of the housing when the shaft is inserted into the bore. On the other side of the housing, a split bushing is provided for receipt within the sleeve, the split bushing including a tapered surface for mating engagement with the tapered surface on the sleeve. A retainer plate is provided that is adapted to be placed on the end of the shaft extending through the bore. The retainer plate has a center hole for receipt of a capscrew through the retainer plate and into the shaft to securely maintain the shaft in place. The retainer plate further has a plurality of holes dimensioned so that the head and shank of screws may extend therethrough and a plurality of holes dimensioned so that only the shank of the screws can extend therethrough.