2004 ford explorer front wheels making clicking noise

SOURCE: 2004 stx f150 right front wheel grinding noise,

I agree with duane_wong on this one ( not like he was looking for my approval :) ), it sounds like a problem with the IWE ( Integrated Wheel End ) on that side.
Quick test, when you are in 4H ( or 4L ) does the noise still happen ?
I would say cracked vacuum line to the IWE, or a problem with the vacuum diaphragm in the IWE. You can test by having the motor running in park, and in 2H, and check the vacuum line at the IWE for vacuum. Make sure you test to the vacuum line, not the vent line ( ends in the engine compartment, not hooked to anything )

This is a block diagram of the IWE vacuum system

Testimonial: "great help!"

SOURCE: Rear Axle Bearing

i know for a fact that the bearing comes with the hub., and if the old bearing is badly damage you may need to heat it to remove it from the axel...so this may be a rather big job if your not equipt
with torch or other ...

SOURCE: front wheel bearing 2004 escape 4x4

It's nearly impossible unless you have a good air compressor and a powerful 1/2" or larger drive impact gun.The reason is you have to remove the cv axle nut and axle out of the way before removing the bearing and hub.The axle nut requires a couple hundred foot pounds to remove.The procedure is:Jack vehicle safely off the ground,remove wheel and tire.Remove axle retaining nut.Remove balljoint nut and bolt,pry down on lower control arm,and disengage balljoint and lower arm from spindle.Now the axle can be released from the hub,but leave the other end of the axle in the trans,just set off to the side out of the way.At this point,there are two ways to change the bearing.The wheel bearing is a double roller,cartridge type with the hub containg the wheel studs,pressed into the bearing.Remove the entire spindle assembly from the suspension strut,OR leave the spindle attached to the strut,and remove the bearing and hub from the spindle.Some guys swear by taking the spindle to a press,and pressing the bearing assembly out with a bottle jack.I just use a bushing driver set,and ball peen hammer,and remove the hub from the bearing...then remove the snap ring retaing the bearing in the spindle,then drive the bearing out of the spindle with the hammer and drivers.There you have it.Reverse procedure for reassembly

SOURCE: Grinding sound in the front end

I had this problem in my 2005 F-150 twice! The first time was covered under the warranty and the second time was out of my pocket! ( close to $500.00!) There is a solodoid u[pp on the firewall that gets water into it then it corrodes the lines and such. Ford dealership replaced 2 valve assemblies, 2 actuator assemblies, and the IWE Solonoid to fix mine. They claim the problem will not come back but that remains to be seen.

SOURCE: 2002 ford explorer-no 4 wheel drive

wheel bearing