Hydraulic Control

Hydraulic Control





The valve body includes the main valve body, the regulator valve body, the secondary valve body, the servo body, and the lock-up valve body. The ATF pump is driven by splines on the right end of the torque converter which is attached to the engine. Fluid flows through the regulator valve to maintain specified pressure, though the manual valve, directing pressure to each of the clutches. The shift solenoid valves A and B. and the A/T clutch pressure control solenoid valves A and B are mounted on the outside of the transmission housing. The torque converter clutch solenoid valve is mounted on the outside of the torque converter housing.

Main Valve Body





The main valve body contains the manual valve, the modulator valve, the 1-2 shift valve, the 2nd orifice control valve, the servo control valve, the Clutch Pressure Back-up (CPB) valve, the relief valve, and the ATF pump gears.
The primary function of the main valve body is to switch fluid pressure on and off and to control hydraulic pressure going to the hydraulic control system.

Regulator Valve Body





The regulator valve body contains the regulator valve, the lock-up control valve, the torque converter check valve, and the cooler relief valve.

Regulator Valve
The regulator valve maintains a constant hydraulic pressure from the ATF pump to the hydraulic control system, while also furnishing fluid to the lubricating system and torque converter. The fluid from the ATF pump flows through B and B'. Fluid entering from B flows through the valve orifice to the A cavity. This pressure of the A cavity pushes the regulator valve to the right side, and this movement of the regulator valve uncovers the fluid port to the torque converter and the relief valve. The fluid flows out to the torque converter and the relief valve, and the regulator valve moves to the left side. According to the level of the hydraulic pressure through B. the position of the regulator valve changes, and the amount of fluid from B' through torque converter also changes. This operation is continued, maintaining the line pressure.





NOTE: When used, "left" or "right" indicates direction on the illustration below.





Increases in hydraulic pressure according to torque are performed by the regulator valve using stator torque reaction. The stator shaft is splined with the stator in the torque converter, and its arm end contacts the regulator spring cap. When the vehicle is accelerating or climbing (Torque Converter Range), stator torque reaction acts on the stator shaft, and the stator arm pushes the regulator spring cap in the direction of the arrow in proportion to the reaction. The stator reaction spring compresses, and the regulator valve moves to increase the line pressure which is regulated by the regulator valve. The line pressure reaches its maximum when the stator torque reaction reaches its maximum.

Secondary Valve Body





The secondary valve body contains the 2-3 shift valve, the 3-4 shift valve, 3-4 orifice control valve, the 4th exhaust valve, and the CPC valve.

Lock-up Valve Body





The lock-up valve body contains the lock-up shift valve and the lock-up timing valve.

Servo Body





The servo body contains the servo valve, and the 1st, 2nd, 3rd, and 4th accumulators.