I'm getting this odd chatter/vibration type noise /rattling when i lift off the throttle and let the gear begin to slow the car down. the second i push the gas back in it goes away. I had the car on a lift and the noise is coming from the t-case . I opened the t-case and inspected and checked everything and it's all good. Any info/help required.

 

My 8 does this too and it pretty much has done it since new. I'm getting close to 120 K miles. A hot day and a long drive gets it in full voice.

So, is this something to be concerned about? I'm a little concerned. I know the transfer cases in the early USDM cars like mine will fail if pushed hard. So I don't do that. I suppose eventually both the transmission and transfer case will require a rebuild. Till then I will drive it.