Hydraulic Control

HYDRAULIC CONTROL





The hydraulic control system is controlled by the Automatic Transmission Fluid (ATF) pump, valves and accumulators in the valve bodies. The ATF pump is driven by splines on the end of the torque converter which is attached to the engine. Fluid from the ATF pump 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 valve body includes the main valve body, the servo body, the ATF pump body, the regulator valve body, the throttle valve body, and the 2nd accumulator body. The throttle valve body is joined with the linear solenoid. The throttle valve body/linear solenoid assembly is bolted on the 2nd accumulator body. The shift control solenoid valve assembly is bolted on the servo body. The lock-up control solenoid valve assembly is bolted on the outside of the torque converter housing.

REAR COVER
The rear cover houses the 1st accumulator, the 1st-hold accumulator, and the Automatic Transmission Fluid (ATF) feed pipes.

LOWER VALVE BODY ASSEMBLY
The lower valve body assembly is located on the bottom of the transmission. The lower valve body assembly consists of the main valve body, the servo body, shift control solenoid valves A/B and the Automatic Transmission Fluid (ATF) strainer.

SERVO BODY





The servo body is located on the main valve body. The servo valve is integrated with the shift fork shaft, the 3rd accumulator and the 4th accumulator, which are all assembled in the servo body. The shift fork installed on the end of the shift fork shaft operates the reverse selector.


MAIN VALVE BODY





The main valve body houses the manual valve, the 1-2 shift valve, the 2-3 shift valve, the 3-4 shift valve, the main orifice control valve, the 2-3 orifice control valve, the 3-4 orifice control valve, the 4th kick-down valve, the 4th exhaust valve, and the servo control valve. The primary functions 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 Automatic Transmission Fluid (ATF) pump body. The regulator valve body consists of the regulator valve, the lock-up shift valve, and the cooler relief valve.

REGULATOR VALVE
The regulator valve maintains a 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.
The fluid from the ATF pump flows through B and B'. The regulator valve has a valve orifice. The fluid entering from B flows through the 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 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 the fluid from B' through D and C also changes. This operation is continued, maintaining the line pressure.

STATOR REACTION HYDRAULIC PRESSURE CONTROL





Hydraulic pressure increases according to the torque is performed by the regulator valve using the 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), the stator torque reaction acts on the stator shaft, and the stator arm pushes the regulator spring cap in the - direction 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.

ATF PUMP BODY
The Automatic Transmission Fluid (ATF) pump body is located on the torque converter housing. The ATF pump body consists of the ATF pump gears, the lock-up control valve, the lock-up timing valve, the relief valve and the modulator valve. The torque converter check valve is located between the ATF pump body and the torque converter housing.

THROTTLE VALVE BODY/LINEAR SOLENOID
The throttle valve body is joined with the linear solenoid which is controlled by the Transmission Control Module (TCM). The throttle valve body/linear solenoid assembly is located on the 2nd accumulator body. The throttle valve body houses the throttle valve.

2ND ACCUMULATOR BODY





The 2nd accumulator body is located on the torque converter housing beside the Automatic Transmission Fluid (ATF) pump body. It contains the 2nd accumulator.