Abstract: A tower drive mechanism is described for a self-propelled sprinkler system having a water conduit elevationally supported by spaced towers. Each tower has a frame with leg members extending downward and outward interconnecting with a cross axle tube. Tandem wheel assemblies are mounted on the frame adjacent respective ends of the axle tube. A single electric motor is connected to one of the wheel assemblies. An interconnecting drive shaft extends through the axle tube interconnecting the wheel assemblies so that the drive shaft does not become entangled with field debris or vegetation. The wheel assemblies and the motor have their individual worm gear reduction boxes.