What is the construction and purpose of automatic transmissions?

Automatic transmissions are drivetrain assemblies mounted between the engine and subsequent drivetrain components. Their typical construction includes a housing, a gear set, a hydraulic system, electronic controls, and a torque converter or clutch packs. The transmission's task is to select the gear ratio according to driving speed and engine load without manual shifting by the driver.

What are automatic transmissions used for?

Automatic transmissions are used for smooth torque transfer and automatic gear shifting while driving. In practice, they affect the comfort of starting, accelerating, and driving in traffic jams, as well as cooperation with vehicle electronics. Without a properly functioning transmission, there may be delays in drivetrain response, jerking, or reduced vehicle performance.

What is the construction and function of a torque converter?

A torque converter is a hydrodynamic element connecting the engine to the automatic transmission. It consists of a housing, a pump impeller, a turbine, and a stator, and in many versions, also a lock-up clutch. Its function is to smoothly transfer drive during starting and to dampen sudden load changes.

How to check the compatibility of an automatic transmission with a vehicle?

The most reliable method is to compare the OEM number, transmission code, interchangeable numbers, and vehicle data via VIN. It is also worth verifying the fuel type, engine version, drivetrain type, and associated accessories, e.g., the controller or selector. This information helps avoid incompatibility during installation.

What symptoms indicate problems with an automatic transmission?

The most common symptoms include jerking during gear changes, delayed starting, noise, vibration, and transmission fluid leaks. In some cases, an emergency mode or failure to shift into a selected gear may also occur. Such symptoms should be checked against the condition of the oil, controls, and hydraulic components.

How to prepare an automatic transmission for installation?

Before installation, check the compatibility of markings, the condition of the housing, mounting points, connectors, and associated accessories. It is also good practice to check seals, oil cooling, and control elements. This makes installation smoother and reduces the risk of mismatch.

Automatic gearboxes

At Global Parts, we offer a wide selection of original used car parts, including automatic transmissions for many popular car brands such as BMW, Mini, Mercedes, Audi, Volkswagen, and others. Our automatic transmissions undergo quality control to ensure you receive a top-quality product.

More information