Hydraulic Control

DESCRIPTION
The valve body includes the main valve body, the regulator valve body, the throttle valve body, the secondary valve body, the servo body and the 1st/2nd accumulator 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 through the main valve body to the manual valve and the servo body, directing pressure to each of the clutches. The shift control solenoid valves A/B and the lock-up control solenoid valves A/B are bolted on the outside of the torque converter housing.





MAIN VALVE BODY
The main valve body houses the manual valve, the 1-2 shift valve, the 2-3 shift valve, the lock-up control valve, the lock-up shift valve, the cooler relief valve, the modulator valve, the CPC (clutch pressure control) valve and the main orifice control valve. The primary functions of this 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 consists of the regulator valve, the torque converter check valve and the lock-up timing valve.

Engine Not Running:

Engine Running:

REGULATOR VALVE
The regulator valve maintains a constant hydraulic pressure sent from the ATF pump to the hydraulic control system, while also furnishing ATF to the lubricating system and torque converter. The fluid flows through B and B'. The fluid which enters through B flows through the valve orifice to A, pushing the regulator valve to the right. According to the level of hydraulic pressure through B. the position of the valve changes, and the amount of the fluid through B' from D also changes. This operation is continued, maintaining line pressure.

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





STATOR REACTION HYDRAULIC PRESSURE CONTROL
Hydraulic pressure increase according to torque is performed by the regulator valve using stator torque reaction. The stator shaft is splined in the stator, 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 regulated control pressure or line pressure. Line pressure is maximum when the stator reaction is maximum.





SECONDARY VALVE BODY
The secondary valve body is located on the main valve body. The secondary valve body houses the servo control valve, the orifice control valve, the 2nd orifice control valve, the 4th exhaust valve, the 3-4 shift valve and the 3rd kick-down valve.





THROTTLE VALVE BODY
The throttle valve body is located on the regulator valve body. The throttle valve body contains the throttle valve B. the throttle long valve and the relief valve.





SERVO BODY
The servo body is located on the secondary valve body. The servo body consists of the servo valve which is integrated with the shift fork shaft, the 3rd accumulator piston, the 4th accumulator piston and the 1st-hold accumulator piston.





1st/2nd ACCUMULATOR BODY
The 1st/2nd accumulator body is located on the torque converter housing beside the main valve body. This body contains the 1st and 2nd accumulator pistons.