Hello all, looking for a little help troubleshooting some issues I'm having with my F-150

Truck Details:
2012 F-150 EB SCrew, FX4
134,xxx miles

Issue(s):
I get a constant hum/whirring noise while driving at part throttle that gets noticeable above 20 mph. The noise goes away as soon as I let off the throttle. I've done quite a bit of research and have been unable to find the root cause. I've checked the IWEs and they appear to be working as designed. Additionally I replaced the rear diff and transfer case fluid and found no abnormalities. I ended up taking it to the Ford dealership in Ogden, UT, and while they confirmed the noise, they were unable to fix it. The dealer replaced the diff fluid (less than 3k miles after I serviced it), checked the pinion pre load, and replaced the transmission fluid.
The other issue I'm having is that I can feel a clunk from the driveline while decelerating. When I serviced the diff fluid, I also pulled the driveshaft and greased the slip yoke.

Does anyone have any recommendations on what I should look for moving forward?

Thanks,

Mitch

 

Check out your u joints. Just had to do mine, no more clunk.