Going uphills, CX-9 make whirring noise

[mrsdubose]

Going uphills, CX-9 make whirring noise/vibration

We have noticed that when driving up the hill going to our house that the 9 makes this whirring/vibration sound. I notice it between 40-45 mph. My husband thinks it has something to do with the gear shifting (it seems to be trying to already be in higher gear at lower speeds). Is this something that I should expect to have happen with a variable timing engine

 

[mrsdubose]

took it to Carmax (since it is still under 30 day warranty) and they are going to send it to a Mazda dealership (since it is still under 3 year/36,000 mile warranty). A technician said something about a "rear differential". We'll see what Mazda says. On a good note though, I got a switch box installed for free through Carmax and I have my sat. radio..