include the condition in which all three rotate at the same speed more specifically the speed of the ring gear is a weighted average of the speed of the sun gear and the speed of the carrier with weighting factors determined by the number of teeth on each gear similar speed relationships are imposed by other known types of fixed gearing arrangements a suggested ratio of gear teeth for each planetary gear set in fig1 is listed in table 1 input shaft 10 is fixedly coupled to carrier 22 output shaft 12 is fixedly coupled to ring gear 58 sun gear 26 sun gear 36 and sun gear 56 are fixedly coupled to one another ring gear 28 carrier 32 and sun gear 46 are fixedly coupled to one another ring gear 38 is selectively held against rotation by controllable brake 62 and passively held against rotation in one direction by one way brake 60 carrier 42 is selectively coupled to sun gear 26 sun gear 36 and sun gear 56 by clutch 70 and selectively held against rotation by brake 64 ring gear 48 is selectively coupled to carrier 52 by clutch 66 and selectively coupled to ring gear 58 and output shaft 12 by clutch 68 as shown in fig2 engaging the clutches and brakes in combinations of three establishes eight forward speed ratios and one reverse speed ratio between input shaft 10 and output shaft 12 an x indicates that the clutch is engaged to establish the speed ratio when the gear sets.