Peanutz

Asking a bit of advise from anyone who has heard a grinding noise when excelerating? The sound is from the driver side front wheel and I only hear it when excelerating around 15 - 20 mph. It goes away when I let off the gas or coast. I initially thought it was the wheel bearing, so I replaced it today. 200.00 later, the noise is still there. Could it be the bearing in the CV boot? Any thoughts are appreciated.

windham14

outer tie rod maybe. But im just naming a part that i know down there that i changed on mine lol

traylorsv

I had a grinding noise in my front wheel and come to find out it was a leaking vacuum line which was causing the 4x4 to try to engage.

60DRB

OP, Most likely you'll find your answer reading through this trouble shooting guide;

http://www.ford-trucks.com/forums/836438-everything-you-wanted-to-know-about-the-iwe-system-and-then-some.html
If the IWE needs replacing, here's how (with tool list and pics);
http://www.f150online.com/forums/2004-2008-f-150/360269-iwes-removal-replacing.html
IWEs are about $80 each online and the new style solenoids are about $30. If you can replace an alternator or radiator, etc, you can do the IWE yourself. The solenoid is just a couple screws type thing to replace.
Lots of people bash the vacuum 4WD system but it's pretty easy to diagnose and repair.

1800Beatdown

I had this exact problem about a week ago and was loosing sleep over it. Happened after I went mudding and some dirt must have knocked it loose. I thought my tranny was starting to go on me. It was only when i replaced my rotors with EBCs that I noticed that the line was unplugged. Was so relieved when it was fixed cause it's so simple.