Raise the car in a horizontal position.
Unscrew the plug using a 17 mm Allen key.
If the transmission oil starts leaking out immediately, then its level is OK.
If not, you need to stick your finger into the hole and check if the oil reaches the hole: sufficient oil level.
If the shortage is greater, top up with the appropriate transmission oil at a gas station or in a workshop.
Left: This is how the oil filter (2) is unscrewed using the clamp wrench (1). The illustration shows the filter of a 4-cylinder engine.
Right: The 6-cylinder engine oil filter (arrow) is located at the front left on the bottom of the engine.
Left: The inspection screw plug (1) of the manual gearbox is located in the direction of travel on the right at half the height of the gearbox housing. The drain screw plug (2) is located at the bottom of the gearbox.
Right: The illustration shows the oil filler plug (1) and both drain plugs (2 and 3) in the rear axle drive of the all-wheel drive Audi 100.
Note: Filling very viscous transmission oil manually using a funnel and a long hose, even with warm oil, is a considerable test of your patience and is therefore not recommended. It is better to use special canisters or a syringe with a built-in hose to add oil.
You don't have to think about changing the transmission oil any more. The transmission is equipped with a reservoir from which any impurities are collected using a magnet. However, the transmission oil must meet certain requirements. Audi prescribes the use of viscosity grade SAE 75 W-90 oil with the specification G 50 (synthetic oil).
(The original version is on the portal «AUDIMANUAL»)