cant figure out a noise
 

i have an 2008 f150 4x4
when i get to about 30 mph i hear a noise almost like when a bearing is going bad. is the best way i can describe it in the front end somewhere.
noise stays the same at 30 through 60 - no difference but it does change pitch here and there
only happens when under load. if you let go of the gas it stops
thanks for any help
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Take a short test run but put it in 4wd first.
if your noise is gone, then you need to troubleshoot your IWE vacuum system because you've got a vacuum leak or check valve problem that is letting one hub partially engage and cause that noise when it shouldn't be.

The wheel bearings are only maybe a year old. And there tight so I don't believe that's it.
also if the vacuum isn't right it usually makes a sound like a stick on a spoke.. clicking noise

That's definitely An IWE problem. got a vacuum leak somewhere not holding the IWE's completely disengaged. Like suggested above while driving on a straight length of road shift on the fly to 4Hi and the noise should go away.

When switched to 4x4 the noise did go away.. you are spot on.. is there a place it usually leaks from? Can it leak from the hub?

Usually it's one of the vacuum hoses that's loose or leaky but it could be a bad check valve.
​​​​​or the hub (IWE) diaphragm.

If you get ahold of a mityvac ( hand held vacuum pump with gage) you can easily test the hubs to see if they hold vacuum. You can also unplug the line from the solenoid down to the hubs and that should hold vacuum with the gauge on it.
if you look up fordtechmakuloco he has a couple videos with the troubleshooting procedures.

https://cimg6.ibsrv.net/gimg/www.f15...633848d36b.jpg
I took this off and spliced the lines together and the noise is gone.. is this the check valve? Do I really need it? And thank you for all the advice.

I had the same problem. Threw money at it at first by replacing the IWE's. Wasn't the issue. I would first check if you can hear the vacuum tank next to the battery release pressure after you turn the truck off. Usually takes three or four seconds and sounds like an exhale or sigh. If you hear that then good. As suggested previously I checked the vacuum lines with a Mighty-Vac. It had a very slight pressure drop so I went ahead and ordered the IWE vacuum line set. Once removed I noticed an area that had melted. Put the new lines on and that problem was solved though I still had a tick-pop-tick sound when I turned to the left. That sound was finally corrected when the various fasteners on the front suspension were tightened.

fordtechmakuloco he has a couple videos with the troubleshooting procedures.

He's very good.