Gear rod rotator systems

The disclosure is directed to top caps for gear rod rotators and polished clamps. Disclosed top caps include an elongated top cap body extending along a central vertical axis, the top cap body including a top face, a bottom face, and an exterior perimeter surface defining an outer perimeter of the top cap body, and a polished rod opening extending along the central vertical axis of the top cap body, the polished rod opening defining an interior circumferential surface of the top cap body and configured to receive a polished rod. Additionally, disclosed top caps include a nesting region along the top face, the nesting region configured to receive at least a portion of the polished rod clamp, and a mounting rim on the bottom face and extending outwardly from the bottom face along a longitudinal axis of the top cap body, the mounting rim including a mounting rim outer diameter, a mounting rim inner diameter, and a mounting rim bottom face. Disclosed top caps also include a top cap sensor mounting port hole configured to receive a top cap sensor module comprising a sensor including a position sensor, a temperature sensor, and a vibration sensor.