I recently purchased my first Ford truck, an '04 Screw Lariat, after driving an Explorer for three years, and I started to notice that when I go over speed bumps or any other slight bump in the road that out of my side mirror i can notice the bed shakes pretty badly. The cab is very smooth though. I checked the bolts in the bed and everything seems ok. Just wondering what it could be? Thanks

 

They are meant to flex and move somewhat. What do you mean "pretty bad"? Does it make any noise?

 

My 05 S-Crew does it too. All the bolts are tight and it hasn't fell off yet so normal I guess.