If you've got transmission oil burning up in the engine, then the crankshaft seals are most likely the problem. Can be other (nasty) things like a crack in the case, but the seals are much more likely.
Also, make sure that you don't have the transmission overfilled... if it's really burning tranny oil, the level is probably low at this point. Still, an overfilled transmission might be able to force oil past the seals.
Hope that helps.
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