The fully automatic transaxle, consisting of an automatically shifted three speed planetary transaxle and a torque converter, was introduced in 1969.
The torque converter is a conventional three element design. The three elements are an impeller (driving member), a stator (reaction member), and the turbine (driven member). Maximum torque multiplication, with the vehicle starting from rest, is two and one-half to one. Maximum converter efficiency is about 96 per cent.
The automatic transaxle is a planetary unit with three forward speeds which engage automatically, depending on engine loading and road speed. The converter, planetary unit, and control system are incorporated together with the final drive in a single housing. The final drive is located between the converter and the planetary gearbox. Driving and driven shafts fit one inside the other in contrast to the manual transaxle in which they are located one below the other. The planetary gear unit is controlled by two multi-plate clutches which make up the third-reverse and forward clutch, a first gear band, a second gear band, and a roller clutch which permits the planetary ring gear to rotate only in the direction of drive.
The transaxle control system includes a gear type oil pump, a centrifugal governor which regulates shift points, a throttle modulator valve which evaluates engine loading according to the intake manifold pressure, and numerous other regulating components assembled in the transaxle valve body.
Power flow passes through the torque converter to the turbine shaft, then to the clutch drum attached to the turbine shaft, through a clutch to a sungear. The output planet carrier then drives the rear axle shafts via the final drive.
Transaxle ranges are Park, Reverse, Neutral, Drive (3), Second (2), and First (1).