Yesterday I noticed a buzzing sound that would increase as I sped up and vice versa. Nothing when still, only when moving. Later that evening I did not hear the sound again. Today, after a car wash, I hear the noise again. It sounds like a buzzing locust. My friend seems to think it's coming from the right front but not totally sure. Any ideas? I'll try to record it later.

 

Right front? As in right front if your sitting in the drivers seat, or right front if I'm standing in front of the truck?

 

Passenger side front.

 

since I see it'e a 4x4, read this;

http://www.ford-trucks.com/forums/836438-everything-you-wanted-to-know-about-the-iwe-system-and-then-some.html

 

First question: when the system is working correctly, in 2wd the CV shafts will NOT spin, correct?

Here is what's happening. I lifted both front wheels off the ground. Started the engine. I spin the passenger side wheel and the CV shaft spins with it. I spin the driver side wheel and the CV shaft does NOT spin with it. I put truck in 4wd. CV shafts now spin with both sides.

So does this pinpoint my problem to the passenger side wheel?

 

ttt