I have a 2000 Mercury Mountaineer, 5.0 V8, AWD, 4R70W trans. - it's starting the dreaded frontend growl/whine and I attempted to check the fluid level in the transfer case. There are 2 ports, one above the other (top is fill. bottom is drain?). Upon removing the top port plug to check the level, I got an ATF shower! There is also a rubber hose that connects from the top of the transfer case to the transmission housing. Is the transfer case connected to the transmission for fluid exchange, or is there a proper way to check/fill/drain this transfer case? It's a Borg-Warner TC (8EB)

 

thye dont share the fluid, but they both use the same TYPE fluid. THe hose might just be a vent to let air pressure out ? It does not transfer fluid thru the hose. YOu probably have leaking seal between the two cases. II would pull the top plug and let oil run out to that level. Put back in, run 50 miles and check again.. If your leak is slow, no problem. If your loosing a lot of fluid, the transmission is going empty!

 

I agree, it appears to be a leaking seal. I drained the TC, refilled it to proper level with fresh Mercon and topped off the trans. with Mercon V. Leak appears to be slow. Anybody ever replaced, or had replaced, one of these seals? Thanx for the reply, Steve.

 

You probably have the trailer tow package. If so, check the transmission lines to the radiator and back to the transmission.

 

The seal between your trans and the transfer case is bad. Not a hard job but not the easiest either. Cheap part though and if you have some mechanical knowledge, can be done in less than a day. Let us know what happens.