AW70 in an '87 wagon. A month ago, I found a leak path in the transmission which grew, bit by bit, from a couple of drops per day to several CCs per day. Every time I tried to track down that leak, all the places I expected to find it looked fine- the inlet/outlet from the tranny to the radiator were dry; the in/outlet from radiator to tranny was dry. Pan and pan gasket were a bit dirty, but were definitely not the source- just too little coming out- to account for the clean, bright red fluid collecting and dropping down the middle of the lines between the tranny and radiator.

Of course the dipstick tube on the other side of the transmission, a chronic leaker due to an ill-formed tube sealing flange, wasn't the source of fluid on the opposite side.

So I finally examined the bracket (between tranny and radiator) that surrounds the transmission cooling tubing. Sure enough, that bracket had worn a hole in the side of the tube over the years. McGyver-fixed that temporarily with a hose clamp and cut section of rubber tubing. If you have a stubborn leak, check the tubes for chafing.