If it's like my (722.369) transmission, you'll drain out about 7 quarts from the pan and torque converter. Measure how much is drained out. To refill (per MB shop manual instructions), pour in 4 qts, start the engine, then pour in the remaining charge. Both transmission case and torque converter will be refilled during this procedure.

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95 E320 Cabriolet, 169K