Rear Differential Failing - Warranty Issues

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Yes, you’re correct. My 2016 CX-5 owner’s manual does have that paragraph with different gear lube spec. But I consider that is part of errors Mazda made when they changed the gear lube spec but failed to modified the maintenance note accordingly. Or I can’t think of a reason why Mazda changed the gear lube to a proprietary type SG1 which is a lot more expensive.

For OP, this won’t be an issue as Mazda has eliminated that piece of gear lube replacement paragraph since 2017 gen-2 CX-5 owner’s manual. At the same time Mazda also reduced the fluid capacity on rear differential from 0.48 quart to 0.37 quart.
 

Kedis82ZE8

'12 GX 460,'07 G35x / '15 CX-5 AWD GT w/Tech Pkg
Contributor
I know it will always be up for debate but I would never consider SG1 basically lifetime fluid but that is just my opinion from a long term ownership perspective. I would change still change it at intervals.
 

Kedis82ZE8

'12 GX 460,'07 G35x / '15 CX-5 AWD GT w/Tech Pkg
Contributor
There is still this potential issue with cracked rear diffs of '17+


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:
2017 Mazda CX-5 GS
The car arrived there last evening. Service called early this morning and said they'd get right on it. Got a call back about noon. They determined that it is the differential, and it is covered by warranty. They said that “Mazda was aware of it, and they had had a bad batch.” New dif should be there Monday, and I should be able to pick the car up Wednesday. No problem no fight.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
The car arrived there last evening. Service called early this morning and said they'd get right on it. Got a call back about noon. They determined that it is the differential, and it is covered by warranty. They said that “Mazda was aware of it, and they had had a bad batch.” New dif should be there Monday, and I should be able to pick the car up Wednesday. No problem no fight.
Another great news for you.

Can you ask the dealer in your next opportunity when they said “Mazda was aware of it, and they had had a bad batch”, what is the TSB or Service Alert for this particular known issue?
 
:
2017 Mazda CX-5 GS
Another great news for you.

Can you ask the dealer in your next opportunity when they said “Mazda was aware of it, and they had had a bad batch”, what is the TSB or Service Alert for this particular known issue?
Yes. I have a few questions for them. I’m also curious about how much oil they will have put in the dif. Did they just put in the Mazda .37 liters, or whatever it is, or do they fill it? What kind of warranty will this new dif have? And, I assume they are exchanging it for a new unit, not just replacing a bearing. I can’t imagine that it would be cost effective to rebuild the differential. It must be a whole new unit, but I want to know. And I too wondered, if you know there is a problem, why isn’t there a TSB about it, and what exactly go wrong on them? I’ll see how much of that I can get answers to.

It just so happens that we will be traveling for a few days, and can take a route back that will make it easy to pick the car up. So other than spending 5+ hours on the phone, this has gone very well.
 
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yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Mine had no cracks, no leaks. I will ask what the problem is that “Mazda is aware of.”
In addition to what the Mazda is aware of, you can also ask if you got the latest version of rear differential since there have been many revisions to rear differential including casing.

And when Mazda gives you a “new” rear differential (or a new engine、transmission, etc.) under warranty, most likely it’s a factory-rebuild; unless MNAO have run out such component and have to give you a brand-new one.
 
:
2017 Mazda CX-5 GS
In addition to what the Mazda is aware of, you can also ask if you got the latest version of rear differential since there have been many revisions to rear differential including casing.

And when Mazda gives you a “new” rear differential (or a new engine、transmission, etc.) under warranty, most likely it’s a factory-rebuild; unless MNAO have run out such component and have to give you a brand-new one.
A factory rebuild is what what I would expect. I was referring to the dealership service department repairing or rebuilding the old one. I think those days are long gone. Generally they just change out one unit for another.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
A factory rebuild is what what I would expect. I was referring to the dealership service department repairing or rebuilding the old one. I think those days are long gone. Generally they just change out one unit for another.
It depends. If you read the discussion about coolant leak on the 2.5T. MNAO started with replacing the entire engine, then some CX-9 owners have to settle for cylinder head replacement on-site at the dealership although one received a whole new engine directly from Japan!

Yeah I definitely prefer a factory rebuilt unit, not the component level repair by a car dealer.
 
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2017 Mazda CX-5 GS
I was told today that Mazda has not “yet” put out a TSB on this issue, but that the information is available to dealers. The car is ready, and we will pick it up tomorrow. I will verify how much oil they put in it, but I don’t think they fill it to the fill hole. I’m going to pick up some SG1 and top it off myself.
 
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2017 Mazda CX-5 GS
So, to wrap this up, yesterday I was told that Mazda has not seen enough of this problem to generate a recall, the word recall was used, but they are well aware that there are a number of these bad differentials out there. Honestly, we had added 4 hours to a long day's drive home in order to pick the car up yesterday, and get it home ahead of a large snow storm coming into western Colorado today. We were trying to get home with as much daylight and as little deer dodging as possible, so I was in a hurry and didn’t ask all the questions I now wish I had. I didn’t find out exactly what is going wrong with these differentials. I did find out that there is no TSB, and no recall. This was the first one this dealer had seen. They only put in the “Mazda recommended” amount of SG1, so I will still have to fill my differential.

All in all, I live in a rural part of the state, 185 miles and three mountain passes away from the dealer. It took a lot of time on the phone to arrange the tow, at least 5 hours with Mazda US and RSA, but once things got moving, the car left here Thursday and was ready to be picked up Tuesday mid-day. I was very happy with the communication and service from both Mazda USA, and Bob Penkhus Motors in Colorado Springs. Roadside assistance seemed much less efficient, but the whole thing worked out better than expected.

Hopefully, the problem, whatever it was, has been fixed in this new unit, since I only have about a year of drivetrain warranty left.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
So, to wrap this up, yesterday I was told that Mazda has not seen enough of this problem to generate a recall, the word recall was used, but they are well aware that there are a number of these bad differentials out there. Honestly, we had added 4 hours to a long day's drive home in order to pick the car up yesterday, and get it home ahead of a large snow storm coming into western Colorado today. We were trying to get home with as much daylight and as little deer dodging as possible, so I was in a hurry and didn’t ask all the questions I now wish I had. I didn’t find out exactly what is going wrong with these differentials. I did find out that there is no TSB, and no recall. This was the first one this dealer had seen. They only put in the “Mazda recommended” amount of SG1, so I will still have to fill my differential.

All in all, I live in a rural part of the state, 185 miles and three mountain passes away from the dealer. It took a lot of time on the phone to arrange the tow, at least 5 hours with Mazda US and RSA, but once things got moving, the car left here Thursday and was ready to be picked up Tuesday mid-day. I was very happy with the communication and service from both Mazda USA, and Bob Penkhus Motors in Colorado Springs. Roadside assistance seemed much less efficient, but the whole thing worked out better than expected.

Hopefully, the problem, whatever it was, has been fixed in this new unit, since I only have about a year of drivetrain warranty left.
Kudos to MANO who did the right thing and didn’t give you a hard time replacing the rear differential under warranty with free roadside assistance which can be very expensive in your situation. I’d also check the gear lube level at rear differential and make sure it reaches the fill-hole according to Mazda Workshop Manual with SG1 if the Mazda dealer filled the differential with only 0.37 quart.

It’d be nice if you can post the repair invoice which lists parts replaced and lube used. It’s great info for many here including me.
 
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2017 Mazda CX-5 GS
Kudos to MANO who did the right thing and didn’t give you a hard time replacing the rear differential under warranty with free roadside assistance which can be very expensive in your situation. I’d also check the gear lube level at rear differential and make sure it reaches the fill-hole according to Mazda Workshop Manual with SG1 if the Mazda dealer filled the differential with only 0.37 quart.

It’d be nice if you can post the repair invoice which lists parts replaced and lube used. It’s great info for many here including me.
I discussed it with them in person, and they said they have to follow Mazda's instructions and not fill it to the fill hole. I told them that everyone just fills it themselves, and that every other manufacturer that I’ve ever dealt with fills it to the fill hole - otherwise, lower the fill hole. I was going to buy some from them, but they want nearly twice as much per quart as I will pay ordering it online. I’ll fill it as soon as I get some. They also did a drain and fill on the transfer case, so now I have to refill that too. I love laying in the snow.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I discussed it with them in person, and they said they have to follow Mazda's instructions and not fill it to the fill hole.
Actually the Mazda Workshop Manual DOES state that fill the gear lube to the fill-hole.


I told them that everyone just fills it themselves, and that every other manufacturer that I’ve ever dealt with fills it to the fill hole - otherwise, lower the fill hole.
Exactly! This’s one thing I don’t like by Mazda’s, the incorrect / inconsistent “approximate” fluid capacities given in specs. The other thing is giving a range instead of s specific value for all torque value.


I was going to buy some from them, but they want nearly twice as much per quart as I will pay ordering it online. I’ll fill it as soon as I get some.
Yeah, the SG1 is indeed expensive!


They also did a drain and fill on the transfer case, so now I have to refill that too.
Based on member’s experience here, if the Mazda dealer did fill 0.48 quart of gear lube as specified by Mazda at front transfer case, the level should be right near the fill-hole. You can verify it and let us know.

But it’s a nice gesture the dealer did that for you.


I love laying in the snow.
Haha! “Love” to do that too when I was younger in Iowa. Not anymore ⋯ ;)
 
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Mazda CX-9 Signature
In my experience, talking to the service advisor is like talking to any typical salesperson. They can recite the label and spew out generic & vague answers.

I'll willing to bet the tech did fill to the hole. Before you buy the fluid, open the fill hole and poke your finger inside and feel the level.
 

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