As far as voiding a warranty goes my dealer told me this...."Its a jeep! We expect people to modify them and beat them. Only if we have to call the warranty companys claims ajuster down here to the dealer, there will be no issues". It sounded to me that the warranty was not jeep but an out sorced insurance company. I have a 5 month old jeep and I will be adding a leveling kit and bigger tires very soon. I dont see any powertrain issues because of that.