Vibration sound when turning

The last few days I've been hearing/feeling a slight vibration sound each time I turn left or right. This is consistent in drive and reverse. Maybe it's been present for some time and I haven't noticed but, I doubt it.

I've checked the fender liners for tire rub...nothing there. It's a bit difficult to isolate the origin of the sound. I did change my rear diff oil last week. Cannot definitively say it has occurred since then but...can this be a factor? After reading through the forum I used the Mobil 1 75-90 with LSD additive as the sticker on my diff indicates to do so.

Should I change that oil again to be safe? Possible power steering?

No leaks whatsoever. Suggested troubleshoot?

Thanks for any Input!

2008 quad cab,Prerunner, V6 4.0, 265 70 17 hankook 115,000mi