A planetary gear train automatic limited slip differential may consist of a main differential, a planetary gear train differential controller, a left axle shaft, a right axle shaft, and a clutch. The planetary gear train differential controller may be composed of a first planetary gear train differential controller unit and a second planetary gear train differential controller unit. The first planetary gear train differential controller unit may be composed of a first planetary gear train and a first overrunning clutch connected to the first planetary gear train. The second planetary gear train differential controller unit may be composed of a second planetary gear train and a second overrunning clutch connected to the second planetary gear train.