Strange hum from front end [Update]

[Update]

Full alignment fixed it. Forgot to take a picture of the before and after report, but the toe was way off on the front drivers side.

I took it to a Firestone locally I have used for balance and alignments before. Overall pleased again, though they did call me and tell me the drive belts were “cracked” and should be replaced, but no hard sell.

Looking at the belts when I got home I don’t see any cracks, but they are certainly not new. I went ahead and ordered a new full set from Rock Auto, with 130k miles and no idea when how old they are I figured it is an easy and relatively inexpensive preventative maintenance ($105 with new tensioner).

[Original]

Overall I’m happy with the new Suburban (TL;DR - had a 2015, sold it and bought a 2015 with 4WD and RED).

After purchasing I was planning on putting on new brakes in front, as part of the justification was more road trips, and those will likely involve some mountain driving. I didn’t go to slotted rotors, just the coated and cryo treated Centric rotors and Posi Quiet pads.

[Short aside on that - I may try out some more aggressive pads, braking is slightly better, but I was hoping for more initial grab.]

Anyway, I noticed a very slight hum from the front drivers side (that I didn’t notice before purchase). Only seemed to be there from 25-45mph, or at least with higher speeds the road noise was louder than the hum, and the noise changed with speed not RPM’s.

My first thought was wheel bearing. There was no other indications of bearing going bad, but bearing seemed like a solid assumption.

So I decided if I was doing rotors, might as well do hubs / bearings at the same time. On the Suburban it is one integrated part, so really only three more bolts once you have the rotors off.

[Bad Oppo - this is literally the only picture I took of the process, and I only grabbed this one to remember the position of the dust shield.]

Even with 100k+ miles the process was pretty easy, only one rounded off bolt head, and since it is a GM product I was able to get a replacement bolt at the local Advance Auto.

That leads to now - the hum is still there, so it clearly wasn’t a bearing. On the plus side I have new hubs / bearings along with all new brakes on the front.

But I still don’t know what the noise is. I plan to go to a gravel lot nearby this weekend and cycle it through 2WD to 4WD modes and drive around a bit, then cycle back to see if the noise changes. It isn’t even loud enough that anyone else riding in the car has noticed it, so it really leaves me puzzled.

Other ideas?

Picture of a lizard that was checking out the living room the other day for your time.