Really strange noise while driving

[Tland4]

Hey all, I'm new to the forum and mainly joined due to the fact that I'm having trouble diagnosing a strange noise coming from our 2017 Mazda CX-5 AWD Grand Touring. The car is my wife's daily driver, and it has about 103k miles.

We replaced the tires about 2 months ago with the same Toyo tires as what comes stock on the vehicle.

My first thought with this noise is that it's being caused by a wheel bearing. The noise started as a humming noise, and has escalated to what you hear in the attached video. This video was taken from the driver's seat while driving about 55mph down the highway. The noise goes up in volume the faster the vehicle goes. It can be heard just about any time the vehicle is moving. It does become hard to hear last 65mph, but I assume that's mostly due to road noise.

I typically do all maintenance and repairs on our vehicles, but I've been pressed for time recently due to work. So I had my wife take to to Firestone for a diagnostic. They said they ruled out wheel bearings and CV axles, and recommended we take it to a dealer for a better diagnostic. I still have yet to be able to check it out for myself. I'm really hoping it's not a bearing in the transmission, but I'm not sure what else it could be if Firestone is correct.

I'd appreciate any thoughts. Thank you!

 

[HyFlyer]

Sure sounds like something in the driveline. Have you checked fluids in transmission, transfer case and rear differential?

It sounds like an expensive noise.

 

[Tland4]

Sure sounds like something in the driveline. Have you checked fluids in transmission, transfer case and rear differential?

It sounds like an expensive noise.

I appreciate the reply. I'm going to make time today and do a run through of those. I can't imagine it being the transmission as it still shifts really smooth. My mind as been on the transfer case (front differential, technically right?), so we'll see what we find.

 

[erhayes]

crossed fingers