Description & Operation
The AW-4 is a electronically controlled 4-speed automatic transmission. Running gear consists of a lock-up torque converter, oil pump, 3 planetary gear sets, clutch and brake units, accumulator pistons and valve body. See Fig 1 . The valve body is controlled by electronic solenoids and a Transmission Control Unit (TCU). The TCU generates and sends signals to the solenoids, according to vehicle speed and throttle position. Fourth gear is an overdrive range providing a 0.70:1 ratio.