25/07/2022
What is a Transmission Valve Body?
A transmission valve body is the brain of an automatic transmission outputting signals to engage the clutch and shift at the appropriate time. There are two types of transmission valve bodies; an electronic valve body and a hydraulic valve body.
What Does a Working Transmission Valve Body Do?
Valve body should work with the electronic solenoids in most newer model cars, trucks, and SUVs. Valve bodies in older vehicles use the governor valve and vacuum modulator valve to regulate and manage proper clutch engagement and shifting. The electric valve body use sensors and the electric solenoid valve to control each of gear’s hydraulic circuits. The Hydraulic valve body controls the output for the driver’s manipulation of the gear shift, for example from park to reverse.
Many other valve components housed within the main transmission valve body can fail as well, so diagnosing the specific issue can take sometimes be time-consuming. This is especially true if no issues are found within the main valve body.
What Other Valve Components are Housed Inside the Valve Body?
Valves inside the main body include:
Throttle valve
Shift valve
Shuttle valve
Pressure regulator valve
Manual valve
Vacuum Valve
Kick down valve
Governor Valve
What are the Warning Signs of a Bad Valve Body?
Trouble shifting into lower gear
gears slipping suddenly without warning
downshifting or upshifting on its own
slow shifting or pausing when you try to accelerate or decelerate
RPMs increase when upshifting
audible banging sound when the vehicle changes gears
check engine light or malfunction indicator light is on and throwing one of these P codes: P2707, P0829, P0715, P0783, P0751