When I bought my truck a little while back there was a bad rattle or bumping sound when I would drive over any thing rough. I had the dealership replace the shocks before I bought the truck but it didnt fix it, from looking around the forum found out that it is probably worn out bushings on the sway bar. Ordered them for $38 and put them on in a couple of hours.
Front left support arm removed.
Front left with sway bar removed.
Front left with new bushings installed.