Geartrain

Power is transmitted from the torque converter to the Ravigneaux geartrain components through the input shaft and forward clutch cylinder.
^ The geartrain contains a compound planetary set connected by dual pinion gears.
^ By holding or driving certain components of the gearset, four forward ratios and one reverse ratio arc obtained and transmitted to the output shaft.





The ratios are as follows:
^ 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, and one mechanical diode).
^ four friction clutches.

Planetary Gearset
The planetary gearset in the transmission is a Ravigneaux-type set consisting of the following components:
^ forward clutch sun gear
^ reverse clutch sun gear
^ a pinion carrier
^ long and short pinions
^ output ring year
Components are held or driven to produce forward and reverse gear ratios.

Input Shaft
The forward clutch cylinder and shaft transfers speed and torque from the converter turbine to the geartrain. This shaft is splined to the turbine on one end and to the forward clutch sun gear and stub shaft on the other cod.

Stub Shaft
The stub shaft transfers power from the input shaft to the planet carrier (through the direct clutch) during third and fourth gear operation.

Output Shaft
The output shaft provides torque to the driveshaft and rear axle assembly. It is driven by the ring gear of the planetary gearset.