General description (Audi 100 C3)

An automatic transmission consists of three main components: a transformer, which is directly connected to the engine; final drive mechanism that contains the differential assembly; planetary gearbox with hydraulically controlled multi-plate clutch and band brake. The gearbox also has an oil pump, which is connected to the impeller of the transformer, this pump supplies transmission fluid to the planetary gears, hydraulic control and transformer. The fluid performs a triple function: lubrication of rotating parts, cooling of the automatic transmission system and providing a medium for transmitting torque. The main gear is lubricated independently of the transmission lubrication system, unlike a manual gearbox, where the main gear is lubricated from the general system.

The transformer is a unit in a non-separable housing that cannot be disassembled. It is bolted to the crankshaft drive disk and replaces the clutch used on an engine with a mechanical transmission.

The gearbox is of the planetary type with a block of epicyclic gears, hydraulically controlled brakes and clutches. The desired gear is selected by a combination of three control signals: a manual valve activated by the gear shift cable, a manual valve switched by the accelerator pedal, and a hydraulic pressure regulator. The gear shift cable and selector lever allow the driver to select a specific gear and adjust the automatic control if necessary. The accelerator control determines the desired gear for a specific degree of acceleration, the regulator determines the desired gear relative to engine speed.

Because of the need for specialized testing equipment, the complexity of some parts, and the need for absolute cleanliness when servicing automatic transmissions, the work an owner can do himself is limited.

[A link to the original source is available on the website: Audimanual.ru]