I recently(by recent I mean 15 days ago), bought a 2014 Jeep Cherokee Trailhawk. The first week the vehicle drove fine! Then I noticed going 70mph+ the steering wheel and drivers seat was noticeably vibrating, and one time I hit a bump(a little bridge bump) going around 75mph and the whole front end of my jeep just started violently shaking to the point I had to slow down to 10mph to make it stop. I also am having trouble putting gas in the tank, it’ll let me put $6 in and then automatically shuts off, and it takes about 15 minutes for that. The dealership I bought it from says the tires are cupped, and the axels need to be replaced(that’s where the shaking is coming from), and the gas thing they have no idea what that’s about and they’ve never heard of it. Has anyone had these issues before and know what the issues were that caused them and how they were fixed?