located between an inside surface of bearing housing 14 and outer surface of rotary mandrel 170 at second diameter 178 of rotary mandrel 170 lower tapered roller bearing 210 communicates with lock nut 200 and lower shoulder 22 on inside surface 16 of bearing housing 14 upper tapered roller bearing 220 is located between the inside surface of bearing housing 14 and outer surface or rotary mandrel 170 at second diameter 178 of rotary mandrel 170 upper tapered roller bearing 220 communicates with upper shoulder 20 on inside surface 16 of bearing housing 14 grease seal 222 is located between upper diameter 24 of bearing housing 14 and minor flange 176 of rotary mandrel 170 lock out plate 230 has an inside diameter that surrounds first diameter 174 of rotary mandrel 170 lock out plate 230 preferably defines a plurality of bolt receiving holes 232 therein a plurality of cap screws 234 are received within bolt receiving holes 232 of lock out plate 230 and within bolt receiving holes 32 of bearing housing 14 cap screws 234 are provided for securing lock out plate 230 to bearing housing 14 a seal such as polypak seal 240 is received within tapered upper chamber.