2012 Silverado CC 6.2L Auto/4x4 Vibration/noise help

[dgrinnell]

Alright guys heres the deal, Ive got a 2012 silverado cc 6.2l that I bought brand new in Dec of 2012 I have 20K on the clock and Im having a vibration and a slight whine noise when I put it in Auto 4x4. It all works but I just dont know if this is normal. So Im going to call the dealer today but would like to get an idea of whats going on and if anyone has had this type of issue.

[04GMCYukon]

I know I'm digging up an old thread, but I have a similar (but maybe not as bad?) experience in my new-to-me 2010 2500 suburban. On the road, if I make the switch to auto or 4 high mode, I can hear some additional noise, and occasionally get a bit of vibration if my foot is on the gas pedal just right at certain road speeds. The extra noise comes and goes immediately when I move the switch between Auto and 2wd mode. What did they determine you're issue is (or is it normal..?)

[Harbinger]

It's the leveling kit. Your CV angles are most likely just slightly too much.

 

I have the RCX 3.5" suspension lift that comes with the Diff drop brackets. I still notice vibration in 4x4 that starts around 80km/h. You can look into some RCV axles (Expensive) or you can just take it easy when your in 4x4 and make sure you're not driving on dry roads.