F150 gurus here? I have this noise. So far it's not the brakes. Its not the iwe. Transmission shifts fine. Engine is new. It sounds like the front diff shaft BUT in 2wd it doesn't move. Here's a video how it sounds. Sorry for the wind. 2005 5.4 3v Welp lol i really hope it's not my transfer case is not bad the noise sounds louder when i turn 4x4 on.

Noise is more apparent when driving at slow speeds. Shifts fine. Drives normal.



https://youtu.be/wCihkAqxlAE

 

Video is not available.

 

Try again please. I just verified it.


I found that its the iwe . Vac leak. Fixed one but the other is tiny. I ordered a smoke machine to find it. I've had lean codes since the engine install.

 

Here's the non-mobile version of the link. Standard links display the video

FWIW, all I hear is wind noise.

 

I can't think of anything that would make a high pitch whine (high noise?) aside from pulley bearings on the motor. Wheels bearings.
I think universal joints moan. I think the differential bearings for the half shafts (diff shaft?) moan more than they sound like a higher pitch sound.

 

I checked and it seems it is the hubs. I have a vacuum leak somewhere. I believe maybe my check valves in the vacum hoses are bad. Thank you guys... I always have an issue here and there lol

 

Disconnect the electrical connector at the solenoid and the IWE will remain locked. That may help narrow down the noise being the hub or IWE.

Your hubs aren't related to any vacuum leaking issues you may have. A replacement check valve for the IWE actuator won't make your hub go silent.




Sorry, just reread your initial post. You stated that the noise is louder when you engage 4x4. If you disconnect the electrical connection, this will lock the hubs. You may experience louder noise by doing this. If so, stop the vehicle and plug in the connector and see if it's better.
I'm just trying to diagnose the IWE (nothing else). But I also don't want you to damage the IWE or HUB during testing procedures.

What part are you talking about when you say "diff shaft". I've never heard that phrase used before. You said IT doesn't move in 2wd. I would like to know which part you're referring to.
Two options are:
Half-shaft (or axle) which connects the differential to the wheel hub (one on each side, left and right)
Front drive shaft which connects the transfer case to the differential