Automatic transmission characteristics by pressure
The pressure in the automatic transmission is an important parameter for its proper operation. It transmits torque through the hydraulic system and controls the operation of planetary gears.
Discharge pressure
The discharge pressure is created by the pump and supplied to the automatic transmission hydraulic system. This is the pressure:
* Provides compression to the clutches that engage and disengage planetary gears.
* Lubricates and cools automatic transmission components.
* Transmits torque from the engine to the wheels.
Drain pressure
Return pressure is the pressure in the hydraulic system after passing through the clutches and other components. It:
* Returned to the automatic transmission tray.
* Checked by a pressure sensor, which sends a signal to the control unit (ECU).
*Used to adjust the discharge pressure.
Control pressure
Control pressure is created by solenoids and sent to various channels to control the operation of the automatic transmission. It:
* Changes gears.
*Engages torque converter lockup.
* Regulates the pressure in the hydraulic system.
Pressure measurement
The pressure in the automatic transmission is measured using pressure sensors located in the hydraulic system. Sensors can be mechanical or electronic.
Pressure values
Automatic transmission pressure values vary depending on the manufacturer, model and operating conditions. Typical pressure ranges:
*Discharge Pressure: 60-120 pounds per square inch (psi)
*Drain pressure: 10-30 psi
*Control pressure: 3-10 psi
Deviations from the norm
Pressure deviations from the norm may indicate automatic transmission malfunctions, such as:
* Low discharge pressure: leaks, pump wear
*High discharge pressure: faulty valves, clogged
* Low drain pressure: faulty pressure regulator, worn clutches
*High drain pressure: clogged, faulty solenoids
Maintenance
Proper automatic transmission maintenance, including regular servicing and replacement of the fluid and filter, helps maintain proper pressure and extend the life of the automatic transmission.