Update: My 2008 Ranger XLT vibrates between 45-60 then via ration diminishes at 65 and over. My mechanic changed all 4 shocked and ball joints, 4 brand new tires, no luck. . The front end does not shimmy or vibrate, this vibration you can feel at feet and in the seat as you drive. My mechanic thinks it can be, to warped driveshaft, unjoints or rear end issues. If I go process of elimination it will cost a small fortune. Therefore that’s why I am reaching out here, any ideas?