I took my 2020 in to the dealer service dept. yesterday to have the rear axle checked for hesitancy in acceleration, bounciness and jumpiness. They let me know that the rear differential needs to be replaced under Powertrain Warranty, due to something loose or broken inside. The repair will take a week or so. He also informed me that I should have my coolant replaced and transfer case serviced, despite Ford's maintenance schedule not requiring this service. He said this is due to condition, mileage and age. I'm not sure if I really need this done for $450.