2007~2015 CX-9 Rear diff problem solved

you are taking about transfer case, just want to make sure you problem really is the rear diff and not the transfer case that is in the middle of the vehicule.

you only remove the front portion from what i can remember. there is no special seal, i used "the right stuff" silicone gasket maker. It can be done in a home garage if you are pretty mechanically inclined. i have a lift in my garage so it was easier.
 
:
2014 CX-9 Touring AWD
Thank you so much for the information, and the quick reply!

It is definitely the rear diff, but thank you for the clarification.

I am considering taking the day off tomorrow to repair the AWD, but I just want to make sure I have an understanding of the task before I have to have a mechanic make a house-call!!!

So here is my plan:


1. Ramp and support rear wheels.
2. Disconnect any remaining wires from rear diff
3. Disconnect driveshaft and supports
4. Drain rear diff
5. Remove front portion of rear diff
6. Solder new wires into terminals
7. Increase gauge of gasket and thread new wire through
8. Clean seal ring
9. Apply sealant and replace front portion of diff
10. Refill diff fluid
11. Reattach driveshaft
12. Connect wires to harness
13. Post successful video to YouTube! (haha)


Does this sound about right?

Again, I cannot thank you enough for the knowledge!
 
yeah it does, i beleive you have to disconnect some exhaust pieces in order to remove the driveshaft but i am not sure, you will see once you get there.
 
:
2014 CX-9 Touring AWD
yeah it does, i beleive you have to disconnect some exhaust pieces in order to remove the driveshaft but i am not sure, you will see once you get there.

Ok. A few weeks delayed, but I am now in the middle of the repair. I have removed all the pieces, but I cant figure out how to separate the coupling unit from the rear differential without destroying the aluminum.

How did you get through the rtv gasket?

Does the coupling unit spin out or just pull out?

Thank you!!
 
man i can't remember but it just pulls out i beleive once you removed all the bolts from what i can remember
 
:
Mazda CX-9 GS AWD
I can validate this repair. Dealer wanted to replace the whole rear diff. for $$$$.
My local independent shop charged a few hours for the wire repair. I told them what the problem likely is so they didn't have to go searching.

Update Nov 2019:
Based on this video, I would expect my shop only fixed the wires external of the coupling the first time. They would not have completely disassembled the unit as shown here. The problem has now reappeared, and the wires have broken flush with the rubber grommet into the coupling. The same shop can't/won't fix it. At least not yet, until I show them the video ;) It's easy, right?
 
Last edited:
:
2014 CX-9 Touring / 2008 Mazda 3 Touring 5-door
Great video! I might be able to use this for reference if I decide to tackle changing out the rear diff mounts myself. Do you think the rear diff mounts can be replaced without having to dissasemble to the drive shaft?
 
:
2019 CX-5 GT 184 2.2 twin turbodiesel auto - Sonic Silver
This sounds very patronising but I love it when someone with no mechanical skills has a go and fixes it themselves. I am a mechanic and I would always recommend doing so because as long as you don*t ruin it or hurt yourself, you*ve got nothing to lose!

All I would do differently is put all thefixing bolts in together and run them up evenly working opposite then 90 degrees etc until they are all up tight. It*s nit picking but it might save something getting twisted. Brilliant and I make quite a few videos and it takes quite a bit of work and time so again, thanks for all your effort.

PS, I reckon your helper *Bolt* was curled up in front of the fire while you were lay on that concrete floor ;-)
 
:
2014 CX-9 Touring AWD
Great video! I might be able to use this for reference if I decide to tackle changing out the rear diff mounts myself. Do you think the rear diff mounts can be replaced without having to dissasemble to the drive shaft?

Late reply, but hopefully, you were able to do the repair. You should have been able to replace the rear diff mounts without undoing the driveshaft.
 
:
2014 CX-9 Touring AWD
This sounds very patronising but I love it when someone with no mechanical skills has a go and fixes it themselves. I am a mechanic and I would always recommend doing so because as long as you don*t ruin it or hurt yourself, you*ve got nothing to lose!

All I would do differently is put all thefixing bolts in together and run them up evenly working opposite then 90 degrees etc until they are all up tight. It*s nit picking but it might save something getting twisted. Brilliant and I make quite a few videos and it takes quite a bit of work and time so again, thanks for all your effort.

PS, I reckon your helper *Bolt* was curled up in front of the fire while you were lay on that concrete floor ;-)

I'm here to learn, so next time, I will follow a more controlled bolt pattern when rebuilding, thank you!

And Bolt, was indeed, indoors by the fire.
 
:
Mazda CX-9 GS AWD
Great job! As usual, the first time is the hardest, but now armed with your video, everyone else can save a lot of time. The wires on mine have broken again, causing an intermittent 4WD light coming on. Based on Puma's information, I had a shop fix the wires a few years ago, but now they've gone again, but too deep inside the coupling to repair. Looks like I have to do this disassembly method next.

It appears from your third video, for reassembly, that you could let the diff pivot on the driveshafts and 'hang' down which would allow easy access to all the bolts and the wires. Is that the case? This would make fixing the wires only much easier, if you didn't have to remove the coupling.
Also your 'mistake' of not lining up the driveshaft and coupling holes is a huge relief to anyone else tackling the job. If you hadn't made it, someone else would've been cursing long and hard.


As I understand from the Ford Waterpump lawsuit there are millions of these engine/drivetrains out there. You would think that someone in the aftermarket would have come up with a remanufactured coupling that you could just swap out quickly. Or even just a wiring connector. I could see shop charging 2 hours labor for a quick swap out of the part.
Mandating replacement the whole diff for a $10 wire assembly is criminal.
 
:
Mazda CX-9 GS AWD
See Puma's photos above:

How is the solenoid affixed to the ring in the coupling? Is the whole assembly removable?
 
About the aftermarket solution for the diff wire, the thing is only us in northern places where there is salt have these problems, where they don't use salt on the roads the problem must not be there.

if you have a flashing awd, that is not it, the wire problem on the rear diff would lit a solid awd symbol. A flashing awd symbol for 10 seconds is a sign the awd system isn't working, so either transfer case or front diff teeth that are chewed up.
 
Last edited: