Q: Fixed wheel bearings and tie rod - still making humming sound front passenger side at 40mph. What else can this be?

Hi there. If this noise still persists, then you either have a tire issue or a differential problem. I usually check the tire tread to see if it is worn unevenly. If it is, then this noise will occur. I would rotate the tires to see if the noise moves with the tire. If it does, then the tire is the problem. If not, then it more than likely has a bad output shaft bearing for the front axle. If you are going to have this repaired, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose the humming sound and let you know what should be repaired.