How to troubleshoot Wheelhub vs CV issue - 2007 GMC 4x4 5.3 130k miles

[taxman9]

Hello,
I'm looking for some troubleshooting guidance. I have a 2007 GMC Yukon SLT2 4x4 with 130k miles (5.3L). I have a sort of "worbbling" sound coming from the front driver's side wheel area. The wheel has been balances, I've checked the brake pads, calipers, rotor, etc and that all looks fine. I hear this sound constantly when driving and there is no vibration in the steering wheel. I've lifted the truck and tried testing the hub by pushing pulling on the wheel and rotor to see if there was any give (ie hub bearing) and it was stout. I even tried driving the figure 8 to see if was worse at some point and it wasn't. When I do rotate the hub with the wheel off I feel a little graininess in the rotation - it still spins and rotates once I give it a whirl but doesn't seem smooth. I've also drained the differential fluid and replaced as wheel. The sound/worble is a little more apparent when slowing down at about the 30 mph mark - it even feels that if I needed to slam on the brakes there would be some grinding (kind of the feeling sound of when a brake pad is so wore down it scratches into the rotor). So I'm down to thinking the hub is bad internally, the CV is bad, or something in the differential. Is there anyway to trouble shoot this without replacing all or really getting into it? THanks!!