First, try tightening the pump cover. When you remove the inspection cover on the bottom of the bellhousing, you'll see a bunch of bolts. Only three are to hold the flexplate to the converter (pump). The rest are to hold the converter cover on. Behind that is a big o-ring. If these bolts are loose, it will leak like holy heck. So, torque these to 25 ft. lbs. and check it out again. Of course, it seems you'll never stop a Dynaflow from completely leaking. If these are tight, you'll have to remove the trans or live with it, because there is also a front pump seal that is a standard lip seal in there.