2003 Suburban 4x4

while driving 30+mph on a road with a slope to the right that requires the driver to maintain a mild steering pressure to the left to stay straight, a groan noise is created identical to a bad power steering pump; but never to the right, just the left.

what I have tried with no luck: front end alignment, new power steering pump, bleed the lines for air, new tires.

here is a video I made to show the issue in action:



please, any advice or ideas would be appreciated.

 

Wheel bearing or hub going out?

 

per your suggestion of bearing I lifted the wheels and checked, they spin quietly and no looseness when pulled. thanks for the idea though.

 

How much slope are you talking about ?

Have you checked the Oil Level in your Transfer Case, and Front Differential ?

 

Per your suggestion I checked the fluids in the transfer case and the front diff. Transfer case was in excellent condition but the front diff fluid looked like it needed to be changed. After the fluid drain & fill the noise is a little quieter and more lower in tone, no metal in the fluid. I hope the diff is not on its way out

 

I don't quite understand why the Front Diff would be the source of the noise, customarily you really shouldn't hear much out of it, unless you're in 4WD. Then, that would pertain more to the Bearings, than the Drive Gearing. But, you can't argue with results, and fresh Oil did that for you.

So, you seem to have a choice...
Start changing out Bearings, or leave it and see what happens.

This is an old Shadetree Mechanics trick...
I don't know if it's possible (lube available) but when we had noise problems in Differentials we could get thicker Lube and use it. I don't know if that's available for a Front Diff now a days, but that's possibly an alternative to costly repairs.