I have a 2004 FX4 with 96xxx miles on it.
As I was driving in to work this morning, I heard a loud pop and felt a thud on the drivers side floor board. It felt like I ran something over so I did not think anything of it. A few miles down the road, I heard a popping noise coming from the left front. I parked the truck and engaged 4x4, which engages but I still hear/feel the same thing. I disengaged 4x4 and put the truck in reverse and the truck did not want to go...it seemed as if the left front did not want to rotate. I looked at other post and it seemd like other similar problems only occur when in 4x4, not in 2wd. Anyone have any ideas? I am pretty much stuck at work without any of my tools, so I might have to get creative today.

On a side note, I test drove a 2011 ecoboost yesterday...maybe the truck knows I am about to trade it in...or was atleast. lol

 

Anyone?

 

Sounds like you were driving on dry pavement in 4X4 a real no no. The gears in the front are different ratio than the rear causing the transfer case to load/bind up. The only way is to back up or block up the truck and run it in reverse until the light goes out. Read your owners manual it'll explain I think. However, this was the only way I've ever heard of from members of a 4X4 club that I belonged to.
I accidentally turned the 4X4 button on my 03' (which is alongside the fan switch) and only went a couple hundred feet and felt it binding up, had to back up at least as far or more before the light went out.
Don't forget to disengage the 4WD button, then pray.
Have a Nice Thanksgiving
Good Luck

 

I only drove a foot or so to check it out. Anyways, it turned out to be a bolt on the caliper sheared somehow and knock the caliper up and was pretty much rubbing on the rotor. Thank God it was a quick and cheap fix, it about gave me a heart attack.