when i drive and hit pot holes, and it sounds like my tailgate is loose and is banging back and forth, but i have check and it is not loose. Then I had someone ride in the back and they said it sounds like its coming from the front passenger side of the bed. I have look underneath and do not see anything loose, and when i lift up on that side of the bed, it feels tight.

Any ideas?

 

Check your muffler.

My mid pipe got bent when I jacked up the exhaust to change a header gasket and the muffler ended up sliding inward a little. It would vibrate up and down, hitting the Heat guard on the bottom of the bed. Which is exactly where you mentioned and makes the same sound you mentioned.
Bent to heat guard up a bit and forced the muffler back into proper position and it was fine.

Hopefully thats all it is in your case.

 

Hmm I'll try that, but it doesnt seem like it would sound like the noise im hearing. it sounds like I've got a bad bushing or something.

 

the only thing I can remember that is on the Front Passenger side is your exhaust and obviously suspension. So check the shox too. I've seen people drive around with a shock just hanging.
Might as well check your u-joints too i guess.

 

The front passenger side of the bed. I really think it is something to do with the bed or a heat sheild underneath that is loose somewhere.

 

spare tire loose?

 

x2 mine was loose before and made a noise like the bed was loose.

 

no spare tire. and the bracket is all the way up against the mount.

 

I remember an old TSB about early NBS's having problems with the beds cracking in the upper corners...I would think that would be highly visible if that was the case though...

 

What about your leaf spring bushings? There are supposed to be small plastic discs on the ends of your bottom leaf.