First Gear (D Range)

FIRST GEAR (D RANGE)
The driving force of the turbine shaft is transmitted to the reverse and forward drum and then to the one-way clutch outer race through the forward clutch. One-way clutch 1 transmits this driving force to the small sun gear, causing the gear to rotate counterclockwise.
The pinion gear of the planetary gear, however does mot revolve around the sun gear clockwise because the planetary carrier is locked by one-way clutch 2.
As a result, the internal gear rotates counterclockwise due to the planetary gear set operation, and the driving force is transmitted to the driving wheels.
During deceleration, the small sun gear rotates at a higher speed than the turbine shaft, causing one-way clutch 1 to freewheel.
As a result, reverse torque from the driving wheels is not transmitted to the engine, so the engine brake does not operate.





Hydraulic pressure operation
Line pressure (7) generated in the oil pump is adjusted by the pressure regulator valve and transmitted to the manual valve, throttle valve, 1-2 shift valve, 2-3 shift valve, 3-4 shift valve torque converter clutch control valve, 1-2 accumulator, 2-3 accumulator, and N-D accumulator.
Due to the manual valve position, line pressure (7) is transmitted to (1) and (3). Line pressure (1) works on the 1-2 shift valve, 3-4 shift valve, and N-D accumulator, and engages the forward clutch. Line pressure (3) works on the 2-3 shift valve. Line pressure (7), driven to the pressure regulator valve, is transmitted to torque converter pressure (23) and sent to the torque converter through the torque converter clutch control valve.