Abstract: A transmission differential includes a pair of output shafts mounted in a casing and non-rotatably received by a pair of bevel sun gears. A plurality of planet pinion shafts are received in apertures in the casing and rotatably support bevel planet gears. The inner end of each pinion shaft has a recess or groove therein. A central disc is positioned between the output shafts and engages the inner end of the pinion shafts to prevent radially inward movement thereof. The disc is received by the recesses to prevent rotation of the pinion shafts. Alternatively, a projection on the inner end of the pinion shafts can be received in a groove on an outer surface of the disc.