Second Gear (D Range)

Second Gear (D range)

Outline
^ The driving force of the input shaft is transmitted to the rear sun gear, causing the rear pinion gear to rotate clockwise and as in 1GR, also causes the rear planetary carrier to rotate counterclockwise. The front internal gear rotates counterclockwise together with the rear planetary carrier. Because the front sun gear is locked by the 2-4 brake, the front pinion gear rotates counterclockwise on its own axis and the front planetary carrier also rotates counterclockwise. This driving force is transmitted to the low clutch before causing the rear internal gear to rotate counterclockwise. Due to this, the output gear rotates counterclockwise and the driving force is transmitted to the reduction internal gear via the idler gear. This rotational speed increases because the rear internal gear rotates faster than when in 1GR.
^ Though the reduction internal gear rotates clockwise, trying to revolve the reduction pinion gear clockwise, the reduction pinion gear tries to rotate clockwise as the load from the vehicle (force that prevents the reduction carrier from rotating clockwise) is applied to the reduction carrier.
^ The force of the reduction pinion gear, which tries to rotate clockwise, tries to rotate the reduction sun gear counterclockwise. However, counterclockwise rotation of the reduction sun gear is locked by the reduction one-way clutch. Due to this, driving force of the reduction pinion gear overcomes the load from the vehicle to revolve clockwise while rotating clockwise, and rotates the reduction carrier clockwise.
^ Therefore, the reduction gear also rotates clockwise and the driving force is transmitted to the driving wheels.
^ During deceleration, torque transmitted from the driving wheels, in the opposite direction of that during acceleration. First, force is transmitted from the driving wheels via the final gear and the reduction gear to rotate the reduction carrier clockwise. Moreover, the force tries to revolve the reduction pinion gear clockwise.
^ The force to rotate the reduction pinion gear clockwise tries to rotate the reduction internal gear clockwise. However, as the load from the engine (force the tries to prevent the reduction internal gear from rotating clockwise) is applied to the reduction internal gear, the reduction pinion gear rotates counterclockwise.
^ Due to the counterclockwise rotation of the reduction pinion gear, the reduction sun gear tries to rotate clockwise. However, at this time, the reduction one-way clutch that is locked during vehicle acceleration becomes free and starts to rotate freely.
^ Due to this, the reduction pinion gear force that tries to rotate the reduction internal gear clockwise is absorbed by the free rotation of the reduction sun gear. Therefore torque is not transmitted to the reduction internal gear and the engine braking is not applied.





Operation
^ With shift solenoid B ON, pilot pressure is applied to bottom end of shift valve B, and the shift valve is positioned on the upper side.
^ Line pressure is applied to the low clutch accumulator, and engages the low clutch through shift valve B.
^ With shift solenoid A ON, pilot pressure is applied to the bottom end of shift valve A, and the shift valve is positioned on the upper side.
^ With shift solenoid C OFF, spring force is applied to the upper end of shift valve C, and shift valve is positioned on the lower side.
^ The line pressure is applied to the 2-4 accumulator, and engages the 2-4 brake through shift valve C and shift valve A.
^ Line pressure delivered to the pressure regulator valve is sent to the torque converter through the TCC control valve as torque converter pressure.