As said, you need an alignment. Look up a truck/trailer alignment center. Took care of mine in no time a year ago. After an 11k mile trip across country, two of my "new before the trip" Sallun tires are wearing a bit more on an inside edge and I need one again. The first time it was only one side of the back axle on the passenger side. This time it is both axles on the drivers side.