4 Wheel Drive/SUVs: 2000 Ford Expedition 4X4 5.4l, ford expedition, transfer case

Question
Vehicle seems to intermittently lose power to front wheels in AWD mode when excelerating. Just started, what's the likely cause?

Answer
The all wheel drive viscous clutch is most likely slipping inside the transfer case. This would likely require a rebuild. This clutch is for the purpose of slipping the front axle while turning in AWD so the front axle doen't bind up like it is in 4 wheel drive and buck.

Matt