Power Transmission / Hydraulic Mechanism

POWER TRANSMISSION / HYDRAULIC MECHANISM

Note
^ All directions of rotation are viewed from the oil pump.

P Position, N Position
The driving force of the turbine shaft is transmitted to the reverse and forward drum. None of the clutches are operating, however, so this force is not transmitted to the output gear. Therefore, the vehicle cannot move.
The output gear is locked because the output shell is mechanically locked by the parking pawl. (In P position)

R Position
The driving force of the turbine shaft is transmitted to the reverse and forward drum, and then to the large sun gear through the reverse clutch, causing the large sun gear to rotate counterclockwise.
The pinion gear of the planetary gear, however, does not revolve around the large sun gear because the planetary carrier is locked by the low and reverse brake.
As a result, the internal gear rotates clockwise due to the planetary gear set operation, and the driving force is transmitted to the driving wheels.

First Gear (Engine Brake not Operation)
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 not 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.

First Gear (Engine Brake Operation)
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 not revolve around the sun gear because the planetary carrier is locked by the low and reverse brake.
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, engine braking operates by the coasting clutch engagement.

Second Gear
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 large sun gear, however, is locked by the 2-4 brake band and thus does not rotate.
As a result, the internal gear rotates counterclockwise due to the planetary gear set operation. It rotates the first gear, and the driving force is transmitted to the driving wheels.

Engine brake non operation
During deceleration, engine braking does not operate because one-way clutch 1 freewheels, similar to driving in first gear.

Engine brake operation
During deceleration, engine braking operates by the coasting clutch operation, similar to driving in first gear.

Third Gear
The driving force of the turbine shaft is transmitted to the reverse and forward drum and causes the small sun gear to rotate counterclockwise through the forward clutch, one-way clutch 1, and coasting clutch.
However, during start-up of the second to third gear shifting, the coasting clutch is not yet engaged. Thus, the driving force uses the forward clutch and one-way clutch 1 for the counterclockwise rotation of the small sun gear. This driving force is also transmitted to the planetary carrier through the 3-4 clutch, making it rotate counterclockwise.
As a result, because the small sun gear and the planetary carrier rotate counterclockwise at the same speed, the internal gear rotates faster than second gear.
The driving force is transmitted to the driving wheels.
During deceleration, engine braking operates by coasting clutch engagement.

Hydraulic pressure operation
Line pressure (7) generated in the oil pump is adjusted by the pressure regulator valve and transmitted to the manual valve, solenoid reducing 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.
With the shift solenoid B OFF, line pressure (3) is transmitted to (13) due to the 2-3 shift valve operation. Line pressure (13) works on the bypass valve to quicken the start-up of the 3-4 clutch application pressure. When the path from (13) to (18) in the bypass valve closes, line pressure (13) goes through the orifice check ball from (13) to (18), line pressure (13) goes through the orifice check ball to work on the 2-3 accumulator, slowly increasing 3-4 clutch application pressure.
With shift solenoid C OFF, line pressure (1) is transmitted to (16) due to the 3-4 shift valve, Line pressure (16) engages the coasting clutch. Line pressure (13) is transmitted to (15) and works on the 2-4 brake released side. 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.
(Below 36 Km/h (22.3 mph))
With shift solenoid A OFF, line pressure (9) which works on the 2-4 brake applied side is drained from the 1-2 shift valve, and releases the 2-4 brake band,
(Above 38 Km/h (23.6 mph))
With shift solenoid A ON, line pressure (9) works on the 2-4 applied side. However, line pressure (15) works on the 2-4 brake released side, and the 2-4 brake band is released due to pressure applied to the difference between the surface areas of the band servo pistons.

Fourth Gear
The driving force of the turbine shaft is transmitted to the planetary carrier through the 3-4 clutch to rotate it counterclockwise. The large sun gear, however, is locked by the 2-4 brake band and thus does not rotate.
As a result, the internal gear rotates counterclockwise due to the planetary gear set operation. It rotates faster than the third gear and the driving force is transmitted to the driving wheels.
The driving force of the turbine shaft is also is transmitted to the one-way clutch outer race through the forward clutch. The rotation speed of the small sun gear (that of the one-way clutch inner race) is higher than that of the one-way clutch outer race. Thus, one-way clutch 1 freewheels and does not transmit power.
During deceleration, the engaged 3-4 clutch transmits the rotation speed of the internal gear and planetary carrier to the engine side, and engine braking is obtained.

Hydraulic pressure operation
Line pressure (7) generated in the oil pump is adjusted by the pressure regulator valve and transmitted to the manual valve, solenoid reducing 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.
With shift solenoid A ON, line pressure (1) is transmitted to (9) due to the 1-2 shift valve operation. Line pressure (9) works on the 1-2 accumulator and 2-4 brake band applied side, engaging the 2-4 brake band.
With shift solenoid B OFF, line pressure (3) is transmitted to (13) due to the 2-3 shift valve operation. Line pressure (13) works on the 2-3 accumulator, and then engages the 3-4 clutch.
With shift solenoid C ON, line pressure (15), which works on the 2-4 brake released side, is drained from the 3-4 shift valve, and line pressure (16), which engages the coasting clutch, is drained from the 3-4 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.

Torque converter clutch non operation
With the torque converter clutch solenoid OFF, torque converter pressure (23) is transmitted to (24) due to the torque converter clutch control valve operation, and works on the torque converter front chamber.

Torque converter clutch operation
With the torque converter clutch solenoid ON, torque converter pressure (23) is transmitted to (25) due to the torque converter clutch control valve operation, and works on the torque converter rear chamber, At that moment, torque converter pressure (24) is drained from the torque converter clutch control valve.