An infinitely variable transmission requiring no external controls is shown in its preferred embodiment of the present invention as including a power housing rotatably mounted on an input and an output shaft. The output shaft includes a planetary cage and planetary gears located in the interior of the power housing. The planetary gears are in gearing relation with a sun gear located on the input shaft in the interior of the power housing and also in gearing relation with a ring gear formed as part of the power housing. Lubricant is provided in the interior of the power housing. If the load is sufficient to cause slippage, the resistance of the load coupled to the input rotation causes the power housing to rotate in a direction opposite to the direction of the input and output shafts when the output is initially accelerated. The internal resistance of the transmission created by the drag and friction of the drive, planetary, and ring gears gearing together and the viscosity of the lubricant influences the rotation and acceleration of the output. As the output load is accelerated and the input r.p.m. increases to a more constant level, overcoming initial load, the output load will decrease proportionately causing the power housing to decelerate. When the output load decreases to a point where there is less resistance to further accelerate the load than the internal resistance in the transmission, the output housing will cease rotation and begin rotating in the same direction as the direction of the input and output as the output is further accelerated.