Ask a Mechanic Online and Get Answers to Your Car Questions
Greetings from Mikey at Just Answer!
You can usually hear a bad wheel bearing with all windows up and driving 40 mph.
A bad wheel bearing noise will change in pitch at 40 mph if the steering wheel is turned slightly to deflect the weight of the car.
If the noise quiets for a moment when steering left than the left bearing is making the noise. For some unexplainable reason it seems to me the left front bearing goes out first.
If there is no change in the noise at 40mph when turning left or right, then you have to think about a transmission final drive noise which is hard to confirm.
Final drive noise often changes pitch (gets quieter) at 40 mph at the moment of throttle between acceleration and deceleration. Sort of when you are not accelerating OR decelerating, but cruising or holding steady throttle.