Overhaul - A/T: Description
AW 55 and BW 55 transmissions are fully automatic 3-speed units consisting of 3-element torque converter, compound planetary gear set, 2 multiple-disc clutches, 2 one-way roller clutches, and 3 multiple-disc brakes. Clutches may use either single or multiple piston return springs,
AW 70 and AW 71 transmissions are fully automatic 4-speed units consisting of 3-element torque converter, compound planetary gear set, 3 multiple-disc clutches, 3 one-way roller clutches, and 4 multiple-disc brakes.
Hydraulic system, pressurized by gear type pump, provides working pressure required to operate automatic controls. Valve bodies will vary in different models.
AW 70 and 71 transmissions are equipped with overdrive. Overdrive is automatically engaged in 3rd gear direct drive and gives drive ratio of 0.69:1. Overdrive will not operate in kickdown 3rd gear (throttle open more than 85%).
Overdrive can be manually disengaged by depressing button on shift lever. This will illuminate "OD OFF warning lamp on instrument panel and remove power from relay to overdrive solenoid on transmission. Relay automatically resets and returns transmission to overdrive mode when ignition is turned off.
Note additional elements of overdrive portion for AW 71. See Fig 1 .