just got done a Fa #5 set screws broke in bull gear and fell into oil pump. drilled out set screws and tapped to 3/8" with one solid set screw then TIG welded the screws in and ground flush. have pictures but don't know where or how to post them. The bull gear is made of three pieces the hub and the two helical gears it is pressed on and drilled on the center line and set screws are put in . only know of one other chiller that has this type of gear i don't think there are to many out there.