[V8] Automatic Transmission Leak

[Gunter Lorberg]

One of my 1990 V8s (135 000 miles) is slowly losing ATF at about the rate of about one quart every 2000 miles.  It eventually finds it way down to the right side of the exhaust system which produces some smoke which is much more evident after the transmission has had to work harder, such as after going up a long incline.
 
Upon first inspection, and before cleaning up the area, it looked as though the source of the leak was the seal of the front input shaft as it entered the front differential.  After I cleaned things up, the most likely culprit became the hose/vent coming off of the transmission on the right side above the front differential.  This seems to be a very difficult area to access unfortunately.
 
I have never seen one of these transmissions out of the car...dealing with that hose would be a cinch in that case.
 
I am writing the list because I wanted to find out if this is a common leak.  I also wanted to find out the function of this hose and where the other end goes to (can't see it myself).  Last, I wanted to know if there were any short curts that others on the list were aware in tackling this job, and for any other tips on this issue.
 
Thanks.........otherwise the machine is running remarkably well........I really enjoy driving it....it is amazing in the wet at 100mph around a sweeping bend.....other cars may now have more power (15 years later) but few can put the power to the pavement like this car in adverse conditions.
 
Gunter
(2) 1990 Canadian V8s