Automatic Transmission Components: GEARTRAIN: Notes

Power is transmitted from the torque converter to the planetary gearsets through the input shaft. Bands and clutches are used to hold and drive certain combinations of gearsets. This results in five forward ratios and one reverse ratio, which are transmitted to the output shaft and differential.

Fig 1: Gear Ratio Table

Courtesy of MAZDA MOTORS CORP.

The planetary gear front carrier is driven by the input shaft. See Figure .

• The front planetary gearset carrier drives the center shaft via the overdrive one-way clutch in 1st, 2nd, and 3rd and 4th gears.
• In 5th, the sun gear is held, causing the pinion gears to rotate around the front sun gear.
• The pinion gears in turn drive the front ring gear resulting in 5th (overdrive) gear ratio of 0.75 to 1.
• The front planetary gearset is internally splined to the coast clutch for engine braking.