Abstract: A downhole vibration tool has an outer housing having an inner surface that defines an inner bore and a flow diverter positioned within the inner bore, the flow diverter having an inner passage and an outer surface that defines a flow path between the inner surface of the outer housing and the flow diverter. A removable plug blocks the inner passage, the plug being removable to open the inner passage. A rotating member is rotatably carried within the outer housing and downstream of the flow diverter, the rotating member comprising a rotor in fluid communication with the flow path and an eccentric mass.