How Do You Clean a Transmission Case?

I don't know either. I have tried the pressure washer, engine de-greaser, carb cleaner, WD-40, brake cleaner, wire brushes, steel wool, emery paper, and a 50 gallon barrel of elbow grease.

So far the internet has been no help. I guess I will check it again in case any new information has been added since yesterday.

UPDATE: Easy Off oven cleaner is the best solution I have found. The one drawback is that it dis-colors the aluminum. This may not be a problem if your planning to paint the case.