My truck has this rattle. I have been hunting it for some time now. Its gotten to me so much I am almost ready to let it go. I got under the truck a few min ago and found that when I hit the bottom of my fuel tank the rattle occurs. I looked for any loose nuts or bolts and did not find any. I looked and tapped on the shield protecting the tank thinking maybe something wedged itself in between the tank and the shield and that is not the case. I am not positive but i think the culprit is within the tank. I do not have a fuel system yet, could this be the signs of a failing pump? I am stumped. please help

 

Have you replaced any shocks lately? Reason i ask is when i replaced mine I had not tighten the nuts enough on the back shocks might want to check them.

Sittingbull

 

2X that! Rears will rattle!

 

So it could be my rear shocks? Guess so. I have never changed them and am at one hundred thousand miles