Bed Rattle

My 2013 double cab short bed 4x4 makes a ton of noise when going over even the smallest bumps.
From what I can tell this is due to my bed bouncing up and down because the bolts that hold the bed down are not tight against the floor of the bed. I tried tightening the worst one as well as backing it out and replacing:

This is the bolt in question which seems to be the problem. Drivers side closest to cab.

Please help! I do not know much about body work and I have not been able to come up with a solution.

 

You can likely put a heavy rubber or nylon washer on it to take up the space. Preferably under the bed.

 

If its been loose for a while it may have some road grime built up on the threads. Take the bolt out and wire brush the threads, put some penitrating oil on it and tighten it down and see if it seats all the way. I'd also spray some cleaner and then pen oil where it screws into. I use my bolts to hold my bed mat down and they have a tendency to be hard to turn over the years due to build up. Any time I take the mat out for a good cleaning I do what I mentioned and they always seat back down fine. But you're correct about the cause of the noise. If you don't get them seated down right they'll cause the bed to make a dull thump on bumps and anytime the frame tweaks a bit.

 

What @ABNFDC said - there is a thread that talks about the issue. The composite bed sits on metal frame - over time bed erodes - bolt protrudes - bed rattles. One fix that makes sense to me: remove bolt - place heavy rubber washer made out of old tire between composite bed and frame - replace bolt and snug back down.

 

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