72k miles on my 4WD Exoedition Max. Started making a buzzing/humming noise in the front end. Goes up and down with RPMs. Really loud between 30-45mph. Dealership is guessing a right front wheel bearing to the tune of $850. If the bearing is supposed to last the life of the vehicle, why is mine pooping out this early? Dealership says it is barely starting to go bad, so it is safe to drive on it for a while longer. If it is barely, why is it so loud? Getting a second opinion on Friday, but overall disappointed. Anyone have similar?