03 Tahoe Z71 transfer case noise

[3joh]

I have an '03 Tahoe Auto 4wd w/ 85k on the clock. I recently started getting a slight hum from the front end at 45+ mph. Put the summer tires back on to make sure it wasn't the rubber making noise and I still have the same noise. Drivers side wheel bearing was recently replaced and I am getting an occasional "service 4wd" on the dash that resets itself. The noise is present in 2wd and all other modes that are selected. If I put the truck in 4hi and try to turn in the driveway I am getting clunking and chattering, is this normal to clunk on a tight turn in 4 hi on dry roads? are these two related or should I be looking at the CV joints for wear?

Thanks,

Jeff