CX-5 Rear differential whining

I see a lot of other people have the same issue at 50+ mph but my diff is a loud whirring/whining noise at around 10mph, is my diff shot or is it the viscous coupler, not sure and need my mazda experts here!!! Thank you!
 
Have you changed the fluid in rear diff to check for any water contamination?


Another TSB to look at


Screenshot 2024-06-23 at 2.38.58 PM.png
 
Yeah... uggh...

Just an example.. look around at the used parts market


s-l1600.webp
 
Yeah... uggh...

Just an example.. look around at the used parts market


s-l1600.webp
is there any way i could save it? how much time do i have until the diff fails, do i need a new breather tube?
 
I am not aware of anyone rebuilding these at home.

Sorry.. I don’t know on how long it will last.

Have you drained and refilled the fluid out of the rear diff yet?

I would install the revised breather tube but that will just prevent further damage if water gets into that spot in the future.
 
I am not aware of anyone rebuilding these at home.

Sorry.. I don’t know on how long it will last.

Have you drained and refilled the fluid out of the rear diff yet?

I would install the revised breather tube but that will just prevent further damage if water gets into that spot in the future.
Where can i buy the revised tube? No i have done the fluid of the diff yet, most def gonna do that
 
Fluid preferences are debatable and borderline on politics & religion :-)……but I use Amsoil in a lot of my applications. This is what I have been using in my CX-5. ‘16+ they started recommending some expensive Mazda fluid for models going forward. Any one of these I would fine using in mine…others will have their own recommendations



 
He has a ‘14… it could have been from a car wash as well.. unless I lived in a desert and only ever hand washed vehicle I’d strongly encourage 13-16.5 owners to retrofit with the TSB parts

 
It may depend on how much water got down there.

It very well could be the TSB you mentioned above as well as the water intrusion is a red herring
 
Yeah... uggh...

Just an example.. look around at the used parts market


s-l1600.webp
Mazda has modified the rear differential front housing to eliminate cause of the noise due to bearing failure since Oct. 2015. @Chris_Top_Her had his 2015 rear differential replaced with a used 2016 CX-5 on purpose as it has revised housing:

What have you done to your CX-5 today?

New diff came in, off aearly build 2016 and the casted model no. is the revised version.
79545055_10162682358795487_3919102626184036352_o.jpg

Unfortunately I seem to hear some whining noise from either rear wheel bearing or rear differential input bearing recently. My 2016 CX-5 GT AWD has only 53K miles and was assembled in Jan. 2015, hence the differential hasn’t been revised on front housing and the potential bearing problem on my rear differential is there.

And it’s funny that he paid $430 shipped for a used rear differential just 4.5 years ago in Dec. 2019, now it’s $1,250??? 😲🥴😵‍💫

no I used some place from CO because the LKQ yards all wanted 180-280 for freight shipping, and I couldn't find any LKQ listing for one on ebay (LKQ listings on ebay are usually free shipping). Paid like 430 shipped for it. There aren't a lot of these used floating around on the net

And a TCM reprogramming is required with rear differential replacement:

Done and done..gonna have my tcm reprogrammed tomorrow with the new diffs text string. Old diff was tore up inside, very black oil but also low viscosity.. it may have had water damage but I've never forced anything (cough uno). So far so good. Also noticed my passenger side brake pad on the caliper side was damn near gone. Probably need to grease slid pins but after two multiple hours sessions I was done wrenching. Contacted brake labs to see if they sell pads only
 
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Fluid preferences are debatable and borderline on politics & religion :)……but I use Amsoil in a lot of my applications. This is what I have been using in my CX-5. ‘16+ they started recommending some expensive Mazda fluid for models going forward. Any one of these I would fine using in mine…others will have their own recommendations



How many quick packs will i need, just one?
 
How many quick packs will i need, just one?
The manual says the gear lube capacity at front transfer case is 0.45 quart. The rear differential is 0.45 / 0.37 quarts on gen-1 / gen-2 CX-5 respectively.

Unfortunately in actuality the rear differential requires ~0.75 quart to reach the fill hole. So you need to get 2 quarts / bottles for both.
 
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