Does your 4X4 Explorer make nise from the front end ? (also posted on FTE)

Does it sound like your truck is being chased by Seagulls ?
Were you told that the seal inside the bearing knuckle is the source ?

Take a look at the following link. It's the part marked #3 in the
illustration.
Link

If so, I think I have the solution which will cost you almost nothing
compared to the 3 hours of work + parts that Ford will charge you.

The 4X4 has a small brass seal that seats inside the steering knuckle. The
CV joint of the front drive shaft goes through this seal and I believe the
seal is there to prevent dirt from going into the front bearing/hub assembly
(which costs almost $270, mind you).

What I think happens is that with time the rubber boot that is protecting
the CV joint dries up and rubs against the seal making that annoying noise.
Mine was so bad I felt like I'm driving on a pier with 50 loafs of bread on
the top of the truck and 100 Seagulls chasing me.

Anyway, to solve this annoying problem all you have to do is get under the
truck right under the drivers/passenger door. Look at the CV joint and trace
where it goes into the steering knuckle. Take some lubricant (I used some
WD-40) and spray a small amount of it right where the rubber boot goes into
the knuckle. Spray a very small amount and watch out not to spray the brake
rotors with it or you will be driving into the fence without the ability to
stop.

I did mine a few days ago. It's a 2 minute fix which will probably last a
few weeks. I used WD-40 just to test and see if I'm correct about the source
of the problem. I've been driving the truck for 2-3 days now and there is
absolutely no noise anymore.

Next time I plan on putting a small amount of grease as the WD-40 will
eventually dry out.