A spindle assembly for the cutter blade of a rotary lawn mower includes a spindle rotatably mounted in a fixed housing by means of a pair of spaced apart tapered roller bearings. Lip seals are provided at the upper and lower ends of the housing and there is a further O-ring seal adjacent the lower housing end. The spindle shaft is maintained within the housing by snap rings and spacers, and the spindle and bearings are lubricated by a heavy oil disposed within the housing. A cutter blade is fixed to the lower end of the spindle and a pulley is fixed to the spindle above the housing.
