2017~2025 CX-5 Rear Differential Failure

[AL Cx5]

It’s still apples to oranges comparison… but comparing a recent production Mazda to recent production Ford, Ram or General Motors trucks, those domestic trucks have some engineering debacles that are inexcusable.
Not sure what you mean by high cost of CX-5 ownership. We had three Toyotas, and basically only paid for routine maintenance/wear. This CX-5 is the third Mazda I have purchased, and I expect the reliability to be comparable to the Toyotas. Let’s hope anyway.

For all of our sake, I hope we have long trouble free service from our CX 5s.

This and other forums are uncovering CX5 issues to be addressed before they are big problems. Unfortunately some folks are paying for our our R&D with expensive repairs or Mazda is fixing their cars.

My to be 20 year old truck has been modified over the years to fix some design flaws. Like the solenoids in the trans. This community is more hands on than I've seen here. As my Ford buddy says, if we could combine all the good features of all the makes, we would have a great vehicle.

I'm glad you have had good luck with your Toyotas. They have had and contine to have significant issues too. This is a Mazda forum and I respectfully want to talk a out Mazdas not debate other brands.

Honestly, I may have not checked my gearbox fluid levels for sometime or until it failed had it not been for this post. Thanks to all that contributed.

My guess is the fluid level got low and the differential failed. The drive train is robust enough if used as a daily driver.

Rigorous maintenance and conscious driving techniques and we have an excellent chance they will last.

 

[AL Cx5]

Today was another Apples and Oranges comparison.

Apples:|
Mazda, I drove to the Stealership and got a quart of trans and gearbox fluids. OUCH! I left $49 lighter.

My wife drove the CX5 this AM so it was all warmed up when I returned. After loosing or removing 8 bolts and the air filter box I could see the trans dipstick. I have this down to 10 minutes but I still cus Mazda. My ride has an extra bolt for the CAI/barometric damper device on the stock air box.

I start the engine. It runs really ruff without the back pressure of the air filter box. I pull the dipstick. It's in the middle and there is a min and max temperature range on the stick. OK, I'll hook up my OBD2 bluetooth and take at trans temp from my phone app. NO GO, NO Trans temp PID. I get the laptop and fire up MazdaEdit software. Again, NO TRANS TEMP! More superior engineering and better manufacturing strikes again!!

I shoot the top of the transmission case with my new. upgrade temp gun. It's within the range on the dipstick. 10 minutes more to button it back up. I stop to admire the complexity engineered in this simple vital procedure.

This seems to be a purpose built PITA to stop the average owner or independent oil change place to do a quick trans level check! I used several combinations of tools most DIY folks may not own.

Same deal with checking, changing the gearbox fluids. Mazda puts a massive 24mm bolt on these wee little gearboxes. Not many DIY guys have box wrenches to 24mm. I so happen to have a large set to do suspension work.

ORANGES:
I changed the trans fluid in my 2500 truck today. Mopar ATF4 fluid is about $8 per quart, full syn on Amazon. Filters are inexpensive as well. I bought a reusable metal pan gasket that always seals. This gasket is at least 10 years old and has 150,000 miles on it. Button up the trans pan and add ATF.

Time to check/trim the trans fluid lever. One only has to reach over the engine and pull the dipstick out. It's right there waiting for the owner to check his trans fluid level! I look on the aftermarket digital dash for trans temp. I trim the fluid to the middle of the hash marks on the dipstick and put it back. I didn't break out one wrench or temp gun.

Is one better vehicle better than the other? Not really the Domestic has it's share of issues. AND many expensive items started around 230,000 miles. I worked through them, now at 285,000 I'm well past the old age, high mileage issues. After modifying and tuning, this beast it gets 23 to 30 MPG highway when driving consciously.

I checked my trucks diff level today. I inserted a 3/8 ratchet into the plug and removed it. No drama, like the Domestic wants the owner to keep up with fluid in this diff and not have expensive repairs. I check the diff level on this 7,000 pound, capable of towing 12,000 #s everyday, with a simple 3/8" ratchet.

I'm on my 3rd aftermarket tuner and have sprung for some custom tuning. I get no pleasure hot rodding a 7,000 barge. I use the tunes to enhance towing and improving FE.

The CX 5 is a delight to drive. It's the right size and more socially acceptable for my wife. The build quality is excellent. I marvel how Mazda went to much expense to secure wiring looms, forged engine parts and so forth. I dropped the front and rear cradles modifying the suspension and saw the build quality up close. Mazda went to great lengths to make the interior and exterior special. I will continue learn how to work around the stuff Mazda engineered to discourage DIY guys.

Will I have the CX5 when it's 20 years old and approaching 300,000 miles. Not likely. I think Mazda engineered this car to have some serious issues near 150,000 miles and 10 years or so down the pike. I hope it proves me wrong. And with the help of folks on this forum we work through the flaws together.

The CX 5 will cost me more to own than the tow pig. It's depreciating rapidly. This turbo requires more frequent maintenance than the turbo truck. Luckily it has a wee little oil pan and differentials. LOL We discussed depreciation before buying and decided to do it anyway. We got Mazda zero percent financing for 5 years. That and an open ECU for tuning got us into a Mazda. We have a Tier 1 tune that put a smile on my face and scares my wife sometimes. Tier 2 is on order.

I have no regrets with our CX 5.

 

[Kedis82ZE8]

I think logic changed ‘17+ but Gen 1 keeps 1% pre-load of power on rear differential at all times as seen in FSM documentation from years back

Also Gen one owners need to make sure they have the water ingress TSB performed that can allow water from a car wash to enter the rear differential vent situated in the lower left area of cargo area.

 

[AL Cx5]

I think logic changed ‘17+ but Gen 1 keeps 1% pre-load of power on rear differential at all times as seen in FSM documentation from years back

Also Gen one owners need to make sure they have the water ingress TSB performed that can allow water from a car wash to enter the rear differential vent situated in the lower left area of cargo area.

Thank you for this tip. I'm going to find this vent hose today.

 

[George___42]

Alright... This is a long thread lol.

Hopefully I'll just add a bit of info for anyone reading.

The Mazda AWD system is very similar to the Toyota AWD system found on most of their FWD based AWD cars (Exception of their newer ones with a driveshaft disconnect of torque vectoring clutch).

It's not a new system and has proven to be very reliable. Lot sof brands do send power to the rear at all times, to enhance driving feel and remove slack from the driveline, so a fast engagement of AWD if slip is detected.

I believe Mazda in particular is pretty aggressive with this being anywhere from 20%-5% if I'm not mistaken. I'll link a few video to quote, as It was a while ago.

Mazda like alot of brands also use the rear brakes in tandem to simulate torque vectoring, and as a result chew through rear brakes. Not uncommon with most modern cars.

I also do remember these rear diff units moved from 80w90 GL-5 to 75w90 GL-4 under the specificed SG-1 gear oil by Mazda around 2015-2016.

I remember reading this being due to concerns over longevity due to the softer metals found inside these rear differentials, prematurely wearing due to the GL-5 fluid previously specified.

GL-5 is typically for differentials so it is odd that GL-4 was used here, as it is often found in transmission due to softer metals used for synchros.

Regardless mine is going on 200,000kms and looks to be in good order (knock on wood).

I'm not sure where your located, based on my experience, America's maintenance guidelines are often far longer or none at all compared to us at the North (Canada) as we follow the severe duty schedule.

On Toyota at the very least, we specify transmission fluid as a service item here, but not in the States... Similarly for coolant and the likes tends to be alot shorter here. Might have something to do with the EPA pushing intervals longer.

Manufacture schedules can often vary what dealers recommend. Hence the discrepancy in what some dealers suggest. I know my local Toyota dealership recommends 8k oil changes vs manufacturers recommendations of 10k.

I'll link a bunch of sources and videos, if you want to get accurate numbers and details, and much of what I'm saying was something I went over a long time ago:

Toyota ATC AWD (Very very similar). Had an experience of tearing it apart and rebuilding one due to failed bearing. Generally very very reliable.

Toyota all-wheel drive. ATC / DTC coupling

Description of Toyota ATC (DTC) 4WD system components and operation

toyota-club.net