A guy at a Cars and Coffee told me my rear shocks were wrong for how I load the truck, and he was right
I load about 300 pounds of gear in the bed of my Tacoma for weekend trips out to Moab, and a guy at a Cars and Coffee meet walked over and asked if I still had the stock rear shocks in it. He said the stock valving was made for an empty bed and that I was hitting the bump stops on washboards without knowing it. I swapped in a set of overload springs and different shocks for around $260 total, and the truck finally sits level even when I'm fully loaded. The ride is a little stiffer empty, but I'll take that trade. Has anyone else found out the hard way that the stock setup on these mid-size trucks just doesn't like constant weight in the back?