When the truck was less than 2years and less than 20,000 miles old it developed a clunking noise in the rear suspension. Sounds like 2 heavy pieces of metal softly being knocked together. The dealership inspected it and replaced both rear shocks. The noise was still there. The dealership replaced the left leaf spring assembly. This temporarily eliminated the noise. The noise came back at just under 3 years and 30,000 miles. The dealership inspected, but couldn’t find the source of the problem. The noise has only worsened since then, and at a recent visit to the dealership, they could clearly hear the problem. I was told that it is the result of worn cushions between the leaf springs. I’m concerned that the truck may be unsafe. I’ve been contacted by GM, and at this time they are looking into how to fix it, and who should be responsible for the repair. I can’t imagine that mine is the only 2020 Silverado with this problem, and think there must be other reports of a similar nature.