I have a 2000 exped 4x4 with 5.4 engine. This vehicle is a full time 4x4. I have a noise comming from the front end that sounds like a bearing getting ready to go out. You can hear it better when the windows are up. I tried to drive along a wall with the window down but could not hear it better. While driving I put the vehicle in neutrual the noise did not change. Applied the brake the noise did not change. Ford has had the vehicle for several days, they could hear the noise but have no idea what it is. They tried a different set of tires and wheels... no difference. Wondering if anyone else has had a simular problem. Thanks Lew

 

While coasting, with lots of room, steer lightly right and see if it gets better or worse, do the same for the left. The dirrection that is noisiest will be the bad bearing, if it is a bearing.

Full time 4x4's used on the road primarily will wear out all sorts of stuff. It could also be in the front axel housing. Gear noise. The difference between a 4x4 and an all-wheel is having the same gear ratio front and back is all wheel drive, and a 4x4 uses a slightly lower gear ratio in the front to pull you through stuff and still being able to steer. Some manufacturer's use the two terms interchangably, like Subaru and Volvo. Check the gear ratios in front and back, i bet it is really an all wheel instead of a 4x4 like the pick-ups.

In '97 the T-case had an all wheel and a 4x4 setting. The all wheel had a clutch in the t-case to slip, so it would not break stuff. I'm unsure of your year.

I think you can tell if it is a real 4x4 vs. all wheel by seeing if it has a low range 4x4. If it has a low range, it is probably a 4x4 not an all wheel. I believe all of the Lincoln Navigators are all wheel, and it was an option on the Expedition.

i hope this helps.....