Rattle coming from truck under heavy throttle

[MMead]

When towing a trailer under heavy throttle, when the t/c is locked up, I hear a rattle coming from the truck that sounds like a loose exhaust piece, but I'm afraid it might be something more serious. I read in another post that a similar sound might be a loose turbo shaft. :{



Has anyone else heard this sound or know what it might be??



My truck is completely stock.



Thanks for the help!