I got sound..loud harmonic whirring sound
Seems....like front end

Gets noticeable about 40 mph and gets louder and starts fading about 50 mph, although it's there before and after that, that's where it becomes noticeable and objectionable.

I've checked all four wheels and there's no play that would indicate a bad wheel bearing

I've run it on jack stands... In two-wheel drive and four-wheel drive, at 40 mph and there's no such noise.

Don't hear any noises turning front or rear by hand either

​​​​​​Front wheel bearings were replaced maybe 40K ago anyway

Shifting into neutral at highway speed the noise is still there it doesn't go away as engine goes to idle. It's definitely drivetrain related.

Oil is clean in the front and rear differentials.... That was changed probably 30k ago anyway but it's clean it doesn't show any signs of having a bunch of metal in it or anything.

It's not tire noise it doesn't change with pavement. It's constant, regardless of the surface you're on.
I did rotate my tires front to back just for grins and it didn't make any difference

I'm out of ideas at how to identify this.... 326 k on truck....

Since it only appears with the load on the vehicle , not on stands, 'lve got to think it's a wheel bearing but I'm at a loss as to why there's no play if ones bad.

At this time my plan is just keep driving until it gets bad enough that it reveals itself.

There doesn't seem to be any slop in the rear drive shaft either... The front drive shaft has quite a bit of slop it seems but it doesn't turn in two-wheel drive so....

Also no change going around corners and either direction although that is hard to do at any high rate of speed.

 

I've changed both of my hub bearing assemblies and there was no noticeable play with either one and they were loud.

 

Can't help with specifics on your truck, but I will throw this out there. I had a car once with noisy front end, replaced the bearings and front cv axles, still made noise. Finally tried over-torqueing the castle nut and was able to get things to quiet down. It was a last resort, but it worked.

 

Post I made a previous post I made in 2021 came back up reminding me that I had some noise from the wheel bearings when I first changed them. I can try upping torque easy enough, at least checking it. Maybe try 250 instead of 225

 

Check the caliper anchor plate bolts up front on both sides. Specially if you didn't replace the bolts in the past once removed. Yeah those are one timers as they require pre applied thread locker.... per Ford service Make sure the big bolts are still present and torqued. Easy enough to check.

I've only heard them at highway speeds when loose. They'll also make a slight knock turning into a driveway at low speeds.