I would jack it up off the ground and make sure all the wheel bearings are good but gabbing each tire individually and moving side to side. I would also have someone turn the steering wheel with the tires on the ground and make sure your tie rods are not word. Check the service records. Look underneath to see if anything is broken. Rotate all the wheels and ensure there are no torn or worn CV Joints or Boots. With the back end jacked up, have someone hold the brake while you turn the rear wheels. The brake will simulate a slight load and will give you an indicator if any of the bearings are going out in the rear. Make sure to turn the wheels back and fourth hard. I was able to see my rear diff/spool was loose and was able to see when the bearings were starting to go in the rear.Lots to look at...those are just some suggestions. I am sure others will have many more ideas.
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