Abstract: A planetary gear transmission for use on automobiles includes an input shaft, an output gear, and three planetary gear trains disposed coaxially with each other and each having a sun gear element, a carrier element, and a ring gear element, two of the elements of each of the planetary gear trains being mechanically coupled to elements of the other planetary gear trains for rotation therewith. The elements which are mechanically coupled to each other provide first through fifth rotating members, the first and fifth rotating members being coupled to the input shaft, one of the second and third rotating members being coupled to the output gear, the fourth rotating member being coupled to the output gear. The planetary gear transmission also has a separating clutch disposed between the elements of the third rotating member, for selectively engaging and disengaging the elements of the third rotating member.