What is a Valve Body?


The valve body consists of an upper valve body, and a lower valve body. The valve body resembles a labyrinth, containing many passages through which the transaxle fluid flows. Many valves are built into these passages, they contained therein control fluid pressure and switch fluid from one passage to another. Normally, the valve body contains the

Primary regulator valve

Manual valve

Shift valves (1-2, 2-3, 3-4)

Solenoid valves (No. 1, No. 2)

Throttle valve

The number of valves depends on the model and some have valves other than those above.

Primary Regulator Valve

1. Roles of components

The primary regulator valve adjusts the hydraulic pressure (line pressure) to each element in conformity with the engine power to prevent pump power loss.

2. Operation

When the hydraulic pressure from the oil pump rises, the valve spring is compressed, the fluid passage to the drain is opened, and the line pressure is kept constant. Also, a throttle pressure operates under the valve and when the accelerator opening angle increases, the line pressure rises to prevent clutch and brake slipping. In the “R” range, the line pressure is raised further to prevent clutch and brake slipping.

Manual Valve

The manual valve is connected with the shift lever and linkage or the cable. Changing the shift lever position switches the fluid passage of manual valve and operates in each shift range.

Shift Level Planetary

Position Gear Unit

P – B3

R – C2,B3

N – –

D – C1

2 – C1,B1

L – C1,B3


In general, cables are used in FF (Front-engine, Front-wheel-drive) vehicles and linkage is used in FR

(Front-engine, Rear-wheel-drive) vehicles.

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