It’s definite related to the axles. I just purchased a 2019 HC z71 package. From the minute I pulled off the lot, I had that jingle sound from 30mph and up. Would go away if I put into 4x4 auto. When I purchased this truck I ordered the GM Trail Boss suspension which also swaps the axles up front , and had to wait for it to be installed. Well it was done yesterday and guess what, no sound at all in 2x4. I hope GM does the right thing here and helps everyone out.
I also had both seals on the transfer case replaced because the truck was leaking trans fluid from the transfer case to trans seal, fluid all over the undercarriage and driveway. It’s been an interesting 500 miles so far. Love the looks and ride of this truck, it’s way better then my 2017 LTZ. Let’s just hope it holds together!!