I posted this on a Silverado forum and haven't had much luck, I was wondering what you guys thought. I have this rattle coming from what sounds like the rear driver's side of my truck. It sounds exactly like a card in a bicycle spoke. The noise only happens after the truck has set for 2 hours or more and it'll last for about 5-10 minutes. I will quit at 30 mph and come back anytime below that. I live on a gravel road and it will stop as soon as I hit the pavement, and when I leave work, which is on pavement it will do it consistently for around 10 minutes. I have walked along side the truck and it sounds like it is coming from the driver's side rear wheel area but I am not sure. The noise is loud and you can hear it with the windows down and it echos off buildings. It has been driving me crazy trying to fix it . So far I have : completely replaced the rear end with a new unit with new axles. replaced both CV axles replaced all brake pads replaced the rear driver's side brake caliper. lubricated every contact point. What could be causing this noise? I am hoping it is not the Sun Gears in the transmission. I would appreciate any input. I have a 2004 Silverado with 200k miles with the g80 rear end 17" factory wheels and tire sizes.