2014, f-150, FX4, 5.0L, 110K miles

2020 changed both front wheel hubs + brakes

Beginning of this year I started to get a hum + vibration in steering wheel, both are more pronounced when turning the wheel right. Even minor as changing lanes, but more so on gradual turns like getting on and off ramps to the freeway. This happens when driving in 2x4. If I place the truck into 4x4, no hum or vibration (outside of the tires sticking more).

So my best guesses were anything rotating on driver side. Thought process here, as I turn right, I place more pressure/weight on the driver side and as result more noise/vibration. So again, thoughts are Wheel Hub (again, but doubtful), cv shaft, or anything related to the 4x4 like the hub actuator on driver side. Went through the hassle, changed Wheel hub, cv shaft, actuator, and new seal between diff/shaft. No difference in hum/vibration. Next plan is to rotate the tires, but the tires are practically brand new as of 2020 or 2021. I had both front/rear/transfer case fluids changed too. No bad reports on condition of previous fluids.

I'm a little lost for words on what else could be the problem. Everything front-end like suspension, etc is still stock and hasn't been changed. New here clearly, I've tried many google searches and not finding anything close to my problem. Most seem to be when in 4x4 or more simple as the wheel hub replaced. So I signed up and posted to hopefully get some help

 

Most likely a 4WD actuator Integrated Wheel End (IWE) since it goes away in 4WD (assume 4A)

 

I replaced the IWE on driver side this go around. Replaced Acuator IWE, Wheel hub (previous wheel hub was only a couple of years old), and CV shaft (plus new shaft seal) at the same time. Result was the same with hum and vibration in 2x4 anything to do with right steering wheel movements/turns. 4x4 everything seems to work fine. Could there be that much vibration from the right side to the point I need to do the same replacements there?

 

I would get a hand vacuum pump and try and activate the IWEs and see if they are holding vacuum or if one is leaking. It would be worth the test to see if one has failed. In my mind, when something fails on my truck on the driver side, most likely the passenger side will fail next so I try and do both parts together.

 

My second thought was the front pinion bearing. Shifting to 4WD should change the feel of a bad pinion bearing because the loading is different, but you stated it goes away entirely so most likely a wheel bearing on passenger side. You mentioned the tires sticking more in 4WD. Are you shifting to 4WD high or 4A? You should have a shop road test it.