Whoa, that's very surprising, usually the first symptom is a foul burning oil smell
and slow drip leak from the breather valve on top.
Did you try reaching the top of the transfer case and see if there was any oil on top?
Also did you use the tiny 1/4" diameter round tube of the electric pump to try to suck out the oil,
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you have to really get it in there, it's about 4-5 inches to get to the bottom of the transfer case.
The oil will not be instantly evident when you remove the plug, you really have to
get the tube into the transfer case as much as you can and angle it downward.
I was only able to get out about half a 16oz bottle the first time I did it.
I'm assuming you never changed the transfer case oil since you bought the car ?
61,000 miles is very low mileage for a 2008, but the OEM oil is 7 years old
and more than likely, the OEM oil turned to sludge like the photos in this link:
http://s159.photobucket.com/user/the_natrix/library/Ford%20Edge%20PTU?sort=3&page=1
You can still try to save it by filling up with new oil and try to dilute the sludge and changing again after 500 miles.
Or if you're mechanically inclined try to disassemble the transfer case and clean it out, but that's way above my skill set.