I have a 2014 v8s that has 92k miles. Every now and then, I'll hear this weird rattle or hum that sounds like it's coming from the rear after hard driving. I wondered if it's a loose bolt or something? Idk. Has anyone else had issues with differentials? I never had the fluid changed which is something I'm going to do. I'm hoping that sound that I'm hearing isn't metal shavings inside.

 

Could be lots of things from your description - Heat shields, exhaust rattles, cross members, or differential. Only way to tell is to get down there and try to isolate the sound source. At 92K a fluid change certainly would not hurt. The diffs on these cars are not really problematic ( any more or less than other cars). Some have had issues, many others have not. Key is always good maintenance.

DC

 

Need to check the vent plug on top to make sure it doesn't become plugged, and push fluid out of the driveshaft seal.