Front End Noise (CV Axles & Bearings..and more)

[KO Phoenix]

I'm a new member with a critical issue on an 06 Tahoe (4x4) that apparently started sometime while I was deployed and my brother was driving the truck in my absence. Over the past week or so my truck has developed a very noticeable loud "grinding/rumble/whining" noise from what sounds like the left front, which I originally thought was a bad wheel bearing and hub assembly. I replaced the left front hub assembly, but the "grinding and rumbling" is still present and after doing some further research (to include asking my brother what all was going on with the truck in my absence), I’m now suspecting the CV axles and bearings were the original culprit all along. However, during my course of troubleshooting, I discovered that the 4wd selector (or some other to be identified component of the 4wd system) apparently failed at some point, because the truck appears to be stuck in “Auto 4wd”. It will shift into 4H and 4L without issue, but will not engage 2H and so my idiot brother had been driving the truck in “Auto 4wd” four out of the six months I was deployed?? While I have taken the time to watch several YouTube videos on how to replace the CV Axles and bearings, I am really concerned about the potential damage to the front differential with the truck being driven how it was. I'm a single military dad who tries to do as much of my own repairs as possible, but admit I might be out of my league with repairs involving the front differential, given its unchartered territory for me and wanted to see if anyone else has experienced either issues and could give me any sincere advice or recommendations. Any assistance will be greatly appreciated. Thanks!

 

[SnowDrifter]

Generally speaking CV axles will make a clicking or popping sound, either when turning or when going to reverse or drive

How's your front differential? Mine sounds like butt. I keep it in 2wd unless I need it.