Mazda 6 noise upon decelerating...could it be a bearing in the transmission?


2014 Mazda 6 with Automatic transmission. 80K miles. I recently replaced the driver-side front hub and bearing assembly thinking that would fix my issue. Nope. I know I have the passenger side I can replace, but before I spend $165 more on an OEM hub, I would like to know what others recommend first.

Let me try to describe the sound.

When you accelerate, you really don’t hear it. Upon letting off the gas, the sound starts. It’s a lower grumbling noise. I thought it was a bad wheel bearing and it could still be on the passenger side. As the car slows down it clearly is louder and louder. I think that’s because the other road noise is almost gone. When you are rolling real slow it is more of a “rough” bearing sound. I’m starting to think it may be a bearing somewhere in the transmission. I don’t know how these FWD transmissions work but I assume there is an output shaft bearing of some sort.

I tested the driver and passenger wheel bearings by jacking it up and trying to move the wheels with hands on 12 and 6 and 10 and 4, etc. Nothing. I’ve used a mechanic stethoscope and placed it on the strut for both wheels. When I did this I heard more grinding on the driver side–thus I replaced that hub.

Take a listen to this video of me recording it as I decelerate from 30 MPH to a stop. It’s hard to pick up via my phone but it is noisy and something I don’t want to ignore. Perhaps I just need to spend the cash and get a dealer to diagnose it. I have “trust” issues with some mechanics since I know a great deal about cars and do not like it when folks are not honest, thus I normally do nearly all of my own repairs.

Link to the youtube that has the sound -->

You need to make your video setting “public” so we can see it.

Fixed. Now public. Sorry about that.

Still doesn’t work.Remove your video then set as" public" ,check your settings.

I got it this time. I failed to click “save” last time.