1997 Chrysler Town and Country Tranny dip stick over flow

My tranny dip stick has begun to over flow enough to be noticible all down the neck of it. The tranny oil gets on the engine and is smoking. The transmission was rebuilt about 6 months ago by Aamco. The problem just started recently. Mainly after driving on expressway. And the day temps have been in the high 80s and low 90s. The tranny was overfilled with too much fluid (2 1/2 quarts) before the problem occured but the fluid was sucked out to level off. Since then it had also begun to slip at shift changes. But now that the fluid is over flowing it seems to be shifting better now. I just don't get it.