Hydraulic Control

HYDRAULIC CONTROL
The valve body includes the main valve body, the regulator valve body, the servo body and the accumulator body. The Automatic Transmission Fluid (ATF) pump is driven by splines on the left end of the torque converter which is attached to the engine. Fluid flows through the regulator valve to maintain specified pressure through the main valve body to the manual valve directing pressure to each of the clutches. The shift control solenoid valves B and C are mounted on the outside of the torque converter housing. The shift control solenoid valve A and the lock-up control solenoid valve are mounted on the torque converter housing as an assembly. The Automatic Transaxle (A/T) Clutch Pressure Control (CPC) solenoid valves A and B are mounted on the transmission housing.

Main Valve Body





The main valve body contains the manual valve, the modulator valve, the shift valve C, the shift valve D, the shift valve E, the servo control valve, the cooler check valve, the torque converter check valve, the reverse Clutch Pressure Control (CPC) valve, the lock-up shift valve, the relief valve, and the Automatic Transmission Fluid (ATF) pump gears. The primary function of the main valve body are to switch fluid pressure on and off and to control the hydraulic pressure going to the hydraulic control system.

Regulator Valve Body





The regulator valve body is located on the main valve body. The regulator valve body contains the regulator valve, the lock-up timing valve and the lock-up control valve.

Regulator Valve





The regulator valve maintains constant hydraulic pressure from the Automatic Transmission Fluid (ATF) pump to the hydraulic control system, while also furnishing fluid to the lubricating system and torque converter. 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 changes. This operation is continued, maintaining the line pressure.

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

Stator Reaction Hydraulic Pressure Control





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.

Servo Body





The servo body is on the main valve body. It contains the servo valve, the shift valve A, the shift valve B, the Clutch Pressure Control (CPC) valves A and B, and the 3rd and 4th accumulators.

Accumulator Body





The accumulator body is on the torque converter housing, next to the main valve body. It contains the 1st and 2nd accumulators, and lubrication check valve.