My 1999 Navigator 4X4 has 105,000 miles and while I was replacing the fuel pump recently I noticed the transfer case output shaft seal was leaking. Today I replaced the seal with an OEM replacement from the local Ford dealer (about $23) and also did a fluid drain and refill with Mercon. The old fluid was surprisingly brown and burnt smelling. I rarely use the 4H and 4L features, but the automatic feature of the unit must be applying the clutches more often than I would have thought. I regret not having changed the fluid sooner. I'm posting this for the benefit of those who haven't given the transfer case fluid a thought.....

after 100000 miles i think you should have changed it more than once

You're a troll. Your opinion is meaningless, and my maintenance schedule is none of your business. I'm hoping you'll be bannedagain soon.

after 100000 miles i think you should have changed it more than once

:wave: