There are multiple fluid cavities in the transmission. This includes automatic transmission fluid (ATF), and gear lube. The ATF is used for the torque converter, the part that couples the engine output to the transmission input. The output of this device is the input to the distributor gear. The distributor gear is aft of the torque converter. The distributor gear has its own cavity. The distributor gear drives: • Output pinion to the final drive-front • The driveshaft through its output drive flange

The final drive-front drives the two front axles. The final drive-rear (rear differential) drives the two rear wheel shafts. - The 4.2Q has three differentials (or sets of gears): 1. Final drive-front 1.4 Qt 2. Distributor gear 0.9 Qt 3. Final drive-rear 1.6Qt - All specify SAE 75 - 90 synthetic gear oil; Audi P/N G 052 145 S2 - The Audi Distributor Gear is akin to a 4WD transfer case; the transmission drives front and rear axles through this center differential The "A8 4.2Q Distributor Gear Seal Replacement Procedure" posted was aimed at the center differential driveshaft seal located at the very rear of the A8Q transaxle assembly. It is apparently prone to dribble gear oil on the LH cat converter. Just FYI, 75 - 90 gear oil is used in extreme pressure applications such as differentials. It is very slick and viscous, and generally has a strong smell. Auto trans fluid is about 20 wt; like motor oil, and is good for hydraulic fluid duty and low shear gear trains. The most common these days is Dexron, which is always distinctly red in color. The A8 calls for "VW ATF"; 10.4 qts new, and 4.2 qts when changed. The rest (6.2 Qts) stays in your torque converter, etc.



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