I don't I posted this anywhere else (not a big poster, mostly use the form for researching new models, potential issues/fixes & lurking). Had to replace the rear diff on our 2014 CX5 at 69,000 km, back in 2016. In the fall of 2015, after installing winter tires in late November, started to notice a 'howl' at highway speeds, usually above 80 km/hr. It got worse as the winter went on, I thought it was the winter tires so didn't do anything about it. When I bought new all-seasons in the spring of 2016 the noise was still there. The dealer replaced the rear diff under warranty. I think it would have been about $2,100 CDN. There is now 178,000 km on the vehicle and will be 7 yrs old in a couple months, bought it in Match 2013. Has been a great vehicle, and I expect that I will replace with another CX5 in 3 years, or possibly a CX30 if Mazda listens and gets the cladding aesthetic corrected.
I have no idea what was the cause of the failure, we don't take the CX5 off-road and we don't recall ever having to drive through any flooded areas of any significant depth. The only 'water-related' issue out of the ordinary was during a road trip to NYC in the summer of 2015. On the drive to NYC, we ran into heavy rain the entire journey, what should have been a 12 hr drive ended up being about 18hrs due to limited visibility, traffic, etc.
Not sure if my comments are of any benefit, bought that I would provide.
Cheers
Update: should have checked my previous postings first, I did post about the rear diff replacement back in May 2016, the actual cost was $1700.
