Ok have a 08 Silverado Crew 5.3L 4x4. Have had this sound for a while, took it in to dealership they replaced engine mounts and something else but the sound is back. Clearly whatever they did didnt resolve the problem. WHen I am backing out of driverway in mornings the left front pops when turn the wheel. Does it no matter which direction i am going. Also pops when driving forwards and am turning almost full lock. What could this be? I would like to get this pinpointed before i go to dealer to get this fixed. Last time they kept truck for 3 days (gave me a loaner) yet still has a problem.