05 f150 4x4
245,000 miles
Changing the transfer case fluid I got a bath when I pulled the plug on the fill hole. Didn't have the drain pan in place yet, so I'm guessing probably 2 quarts hit the floor. Trans level was mid stick. It has to be the transmission rear internal seal.
Anyone have this issue?

 

My 2002 experiences a little leakage. When I change the Transfer Case fluid, it's a little over full. So far I've ignored it. Yours may be excessive and you might want to think about replacing the seal. Ford does specify different fluids.

 

Ford specifies Mercon LV which supersedes Ford Transfer case fluid. LV has the required additives. I am quite perplexed how that much got from the trans to the transfer case without dropping the trans fluid level. It's not something I check regularly since there's no leaks showing under the truck, apparently it been happening for a long time.

 

My '77's C-6 leaks a little into the NP205 married to it, I drain and change the transfer case lube occasionaly, put fresh in. I keep an eye on C-6 fluid. They take different lubes.

 

The transfer case input shaft seal is probably bad. When they fail, transmission fluid leaks into the transfer case and overfills it.

 

The interwebs revealed the cause.
Changing it with the truck on jack stands is going to be a bit claustrophobic. $20.00 for a name brand seal and gasket Ford didn't have.
it $40.00 for 2Qts Motorcraft Mercon LV which supercedes Motorcraft Transfer case fluid.
LV has the additives to prevent foaming that will cause damage over time to the TC Mercon V doesn't have.