Hydraulic Control

GENERAL
The hydraulic control system is controlled by the ATF pump, valves and accumulators in the valve bodies. The ATF pump is driven by splines on the left 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 main valve body, the secondary valve body, the regulator valve body, the servo body and the lock-up valve body are bolted onto the torque converter housing. The accumulator body is bolted onto the torque converter housing next to the other valve bodies. The throttle valve body is joined with the linear solenoid. The throttle valve body/linear solenoid is bolted onto the outside of the transmission housing. The shift control solenoid valves A/B and the lock-up control solenoid valves A/B are bolted onto the outside of the torque converter housing.





MAIN VALVE BODY
The main valve body consists of the manual valve, the 1 - 2 shift valve, the 2 - 3 shift valve, the modulator valve, the 2nd orifice control valve, the cooler relief valve, the lock-up shift valve and the 3rd kick-down valve. The primary functions of this valve body are to switch fluid pressure on and off 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 consists of the regulator valve, the torque converter check valve and the lock-up control 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'. 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.

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





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 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 is located on the main valve body. The secondary valve body consists of the 3-4 shift valve, the 4th exhaust valve, the 2nd kick-down valve, the main orifice control valve, the servo control valve and the servo orifice control valve.





SERVO BODY
The servo body is located on the secondary valve body. The servo body consists of the servo valve, and 3rd, 4th and 1st hold accumulators.





LOCK-UP VALVE BODY
The lock-up valve body is located on the regulator valve body. The lock-up valve body consists of the lock-up timing valve and the relief valve.





ACCUMULATOR BODY
The accumulator body is located on the torque converter housing beside the other valve bodies. The accumulator body consists of the lubrication check valve, and the 1st and 2nd accumulators.





THROTTLE VALVE BODY/LINEAR SOLENOID
The throttle valve body is joined with the linear solenoid which is controlled by the TCM. The throttle valve body/linear solenoid assembly is located on the outside of the transmission housing. The throttle valve body includes the throttle valve.