2000 C5 Automatic 24,000 miles: Need help finding a noise that comes from the rear end area that sounds more like a sharp cracking sound. It does not do it all the time, for example when you hit a pretty good bump it is not there. But simply a small one may evoke the demon to sound off. It also seems to do it more on a left hand turn or shortly thereafter. I have checked all the areas I could get my hands on and all seem tight. Changed fluid and added the limited slip additive but to no avail. rear anti sway connectors seem good, end play seems Ok! It is getting more serious as time goes on. Any help would be appreciated. Thanks

 

Maybe a cracked rear spring?