Ok, so my 1997 has had this "wandering" problem on the expressway, everytime I changed lanes from the right lane to the left the back of the truck felt like it was kicking out from under me.
Cheked tire PSI, good, rotated tires, looked under the truck, checked everything, felt for play, giggled and wiggled, nothing.
Lived with it, hated it, checked for broken springs, loose shocks, bad shock bushings, suspension bushings, you name it I looked.
So today I took it to my guy at the suspension/muffler shop.
He drove it, through it on the hoist, checked, poked, proded.
Found it, fixed it for free.
Loose trailing arm bolt on the right side. He tightened it and all is good.
Without a hoist I never would have found it.

 

That is a person to let others know about.
I would have thought that the loose nut was behind the wheel inside.

 

I tell all kinds of people about this guy.
He even lets me buy my own parts and just charges my labor, cheap labor if I pay cash.
He did my wheel bearings a year ago, both sides, inner and outer, $60.

 

Another good reason to, once a year, crawl under your truck and retorque everything you can reach.