These worm drives are lubricated by oil from 1/8" dia. copper tubing that is fed by a piston pump located in the apron. the worm gear and worm wheel on the left were replaced as they had been operated dry and the worm wheel was displaced from its proper operating plane. Someone had fitted a ball bearing that lacked a snap ring. The ball bearing moved and the worm wheel followed. When this occured, the contact geometry between the worm and its wheel became hopelessly in error.