Transfer Case Fluid gushed out when top plug removed

I have a 2001 Expedition 4 x4 w/5.4. I just changed the transmission fluid and filter and decided to change the transfer case fluid as well. I checked if the drain plug (which is the lower one) would come loose and it did and I tightened it back up. I checked if the fill plug ( the higher one) would come loose and it did and I decided to take it completely out to assist with the draining of the transfer case and it would have to come out anyway to refill. When I did the oil came gushing out like the level was way above the hole. By the time I got the plug back in it looks like a quart came out on the floor (I didn't have a pan to retrieve it yet because I did not open the drain plug.) I thought the level was supposed to be at the bottom of the fill hole. I don't know how it could have been filled above the plug level and there were no leaks. I am confused. Any insight would be helpful. Thank You.

That is odd. But you can't really fill it up any higher than the fill hole anyways so I wouldn't worry too much about it. They might have just filled them as much as possible before installation at the factory, not expecting anyone to take the top plug out first. Though it makes sense to let it vent.

I don't think you are doing anything wrong.

Only if the recent owner went in really deep water and (it)in came in through the ventilation hose. Or as fordandpolaris said, the factory filled it as much as possible. When I refill the transfer case / rear end / front end I fill it fast and put the plug as it drips.

If the fluid is hot you will get some out of the fill hole when you remove the plug, but not a quarts worth. Check the fill level again when cold, add if necessary.

Thank You to all who replied. The only other thing I could think of is if the previous owner filled it while the vehicle was on a forward slope. Anyway I drained it and got a whole two quart out of it. I need to go but some transfer case fluid.

Does anyone know the capacity to the bottom of the fill plug so I know how much fluid to buy? Thank You

Its transmission fluid don't forget... 3 quarts (2 quarts and a little more)

read your owners manual and you will see its 2 quarts not 3

Transfer case
fluid
Motorcraft
MERCON ATF
4x4 vehicles 1.9L (2.0
quarts)

Thank You for the info. BIG BREEN FORD & roxy1225.

Could the rear seal for the tranny leak into the transfer case?

I don't know. If that is possible that might explain the excess fluid in the transfer case.