Abstract: A gear coupled, counter-rotating vibratory assembly is described for producing a fine tuned accurate linear vibratory motion without any twisting force component. The assembly has two parallel shafts that extend through a gear casing with cantilevered ends extending outward from both sides of casing. Large intermeshing gears are mounted on the shafts to rotate the shafts in counter-rotating synchronized motion. One of the gears has metal teeth and the other gear has plastic teeth. Identical eccentric weights are mounted on the cantilevered shaft ends outside of the gear casing at the same angular positions to generate the linear vibratory motion. The eccentric weights on the drive shaft are offset inward of the weights on the driven shaft. The radius of each of the eccentric weights is greater than the radius of the gear but less than the diameter of the gears.