Recently my 2014 CX-5 has been making some noise that increases in pitch from about 30 mph and up. I have seen videos where this has happened with other makes and it was determined to be a rear diff issue due to wear. is there any good source of info regarding this? is there oil to be maintained in the rear diff, or could it be a CV going on one side? Appreciate any experience with this others have had.

 

This issue cannot be compared to other platforms for various reasons.
This is not a common problem with Mazda in normal service life.
If you have not exactly determined where the sound is coming from by lifting your Mazda on a shop lift and doing the proper inspection and testing, then take it to a service shop for evaluation and inspection of the noise. they will also look for wear indicators and anything related to the noise you are hearing.

I would suggest in the future when asking for help include all the important information about your vehicle like mileage which in this case is important.

 

fair enough, the vehicle just turned 90k miles.

 

How many times did you get the transmission serviced?
How many times did you get the rear differential serviced?

If the answer is ZERO then you can add to my example of why both these systems are NOT lifetime no service and should be service at regular intervals.

ASE