Description & Operation: GEARTRAIN: Notes

Power is transmitted from the torque converter to the Ravigneaux geartrain components through the input shaft and forward clutch cylinder.

• The geartrain contains a Ravigneaux planetary set connected by dual pinion gears.
• By holding or driving certain components of the gearset, four forward ratios and one reverse ratio are obtained and transmitted to the output shaft. The ratios are as follows:
  Fig 1: Identifying Geartrain Gear Ratios

  Courtesy of FORD MOTOR CO.
• Components of the geartrain can be held by bands or clutches and driven by clutches only.

The 4R70W uses:

• Two bands.
• Two one-way clutches (one roller, one mechanical diode).
• Four friction clutches.