Changing CX-9 transfer case gear oil (photos)

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Mazda CX-9
Very strange results. As I mentioned earlier I change the T-case fluid on both my 2011 and 2008 CX-9's last week. I decided to take the plug out and have a look at the magnet since doing so. Originally, there wasn't much crud on the magnet. But since changing the fluid it now has a ton of gunk on it. Weird. This is on both the CX9's since changing the fluid and only a few hundred miles were put on both. About 5 times more gunk than before. My initial thought is that the fluid level was too low to get much on the magnet collector, thus when the level was increased it now is starting to clean up the case and therefore there is more gunk now than before.

Thoughts?

no one have any ideas?
 
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CX-9 2013 AWD
Very strange results. As I mentioned earlier I change the T-case fluid on both my 2011 and 2008 CX-9's last week. I decided to take the plug out and have a look at the magnet since doing so. Originally, there wasn't much crud on the magnet. But since changing the fluid it now has a ton of gunk on it. Weird. This is on both the CX9's since changing the fluid and only a few hundred miles were put on both. About 5 times more gunk than before. My initial thought is that the fluid level was too low to get much on the magnet collector, thus when the level was increased it now is starting to clean up the case and therefore there is more gunk now than before.

Thoughts?

no one have any ideas?
That would seem like the logical explanation, since there's no drain plug and that magnetic fill plug is pretty high up. It would explain that after you refilled with new gear oil and increased the oil level high to the plug, the plug would see 5 times the gunk. So seems like the oil changed is working and doing it's job to dilute the old sludge. Probably best to suck out the oil and refill after another 1000 miles.
 
To follow up on the more sludge on the plug thought. I just did my transfer case today and it was the second change for me. First was about 25K and today was at just about 50K.

I too noticed that the plug had more sludge this time than the first time with the original fluid. However, my fluid was also in much better shape this time. Actually pumped pretty easy and when I poured it into the recycling bin it was much more 'liquid' than the last time. This may support the theory that the first change cleaned things up a bit by flowing better and this time around I was removing the results of that process. Sounds as good a theory as any to me.

I'm going to stick with the 25K interval as it does seem to be producing good results for me and my 2012 CX-9.
 
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CX-9 2013 AWD
To follow up on the more sludge on the plug thought. I just did my transfer case today and it was the second change for me. First was about 25K and today was at just about 50K.

I too noticed that the plug had more sludge this time than the first time with the original fluid. However, my fluid was also in much better shape this time. Actually pumped pretty easy and when I poured it into the recycling bin it was much more 'liquid' than the last time. This may support the theory that the first change cleaned things up a bit by flowing better and this time around I was removing the results of that process. Sounds as good a theory as any to me.

I'm going to stick with the 25K interval as it does seem to be producing good results for me and my 2012 CX-9.
Good to know, thanks for info and good news, did you use the $20 electric pump or hand pump to pump out the used oil? Just wondering about the longevity of that electric pump and if used one time and the residue oil well cause it to fail after just one time, did you use it at 25k and the 50k change?
 
Good to know, thanks for info and good news, did you use the $20 electric pump or hand pump to pump out the used oil? Just wondering about the longevity of that electric pump and if used one time and the residue oil well cause it to fail after just one time, did you use it at 25k and the 50k change?
Actually I am using a "Topsider" like vacuum to remove the transfer case oil. It's the same one I use to change oil on an Audi that has a pump the engine oil out kind of system. First car I saw with this kind of oil change was a Mercedes back in 2004. Anyway, I use the unit with the thinnest vacuum hose that it comes with. I snake the tube over the cross-mount under the vehicle so I can put it into the access on the transfer case in as downward a direction as possible. I have found that it does a good job of getting the oil out.

I also should note that I work on it with things as warm as possible. Usually about 1/2 an hour after a normal drive the exhaust is cool but the oil in the transfer case is still warm so it's easier to pump. As others have said I pump in extra oil on the refill to try to flush things a bit more.

Hope that helps.
 
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Mazda CX-9
That would seem like the logical explanation, since there's no drain plug and that magnetic fill plug is pretty high up. It would explain that after you refilled with new gear oil and increased the oil level high to the plug, the plug would see 5 times the gunk. So seems like the oil changed is working and doing it's job to dilute the old sludge. Probably best to suck out the oil and refill after another 1000 miles.
To follow up on the more sludge on the plug thought. I just did my transfer case today and it was the second change for me. First was about 25K and today was at just about 50K.

I too noticed that the plug had more sludge this time than the first time with the original fluid. However, my fluid was also in much better shape this time. Actually pumped pretty easy and when I poured it into the recycling bin it was much more 'liquid' than the last time. This may support the theory that the first change cleaned things up a bit by flowing better and this time around I was removing the results of that process. Sounds as good a theory as any to me.

I'm going to stick with the 25K interval as it does seem to be producing good results for me and my 2012 CX-9.
This makes sense to me too. I just changed it again after about another 250miles on my wife's 2011 and it was again very nasty looking (the magnet plug). The fluid though as mentioned was much better looking overall. Just starting to turn dark, but somewhat still clear/cloudy/black looking. So my plan is to run it for a while now, maybe 5000miles and do it again. I've gotten pretty fast at this and its quite easy once my arms are used to contorting into the strange positions to get the job done. I also went ahead and put a remote spin on oil filter on the transmission as that fluid looked like total garbage. The transmission is sealed, so go figure. This takes the normal screen filter and makes it obsolete. Felt good to put some real filtration on it.

Doing this has made me wish that there were an option to put a remote filter system on the T-case. There would need to be a 12-volt pump running from the battery of course and a reservoir somewhere, but seems might be worth it to make the fluid changes on the T-case even simpler to me. Also this would add significantly to the fluid capacity which I think is the main culprit to the fluid going bad problem on these vehicles.

Anyone have some good ideas of how or if this might be worth the effort? I wonder if the main plug could be used to put a dummy plug in that had both a 1/4" inlet and outlet tubes plumbed into it, so the fluid could be pulled out and circulated back into the case... have to think this through a bit. Seems like there might be an easy solution that could work.
 
With regard to the ability to pump and filter the transfer case fluid I would imagine the most perplexing part of that would be finding the best way to fabricate the pickup tube to get to where the fluid is in the bottom half of the transfer case. Based on my brief experience in changing the fluid twice it seems to me that the gearing is pretty tight against the case of the unit and there is a very small margin to get the drain tube in there to suck out the fluid.
 
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Mazda CX-9
With regard to the ability to pump and filter the transfer case fluid I would imagine the most perplexing part of that would be finding the best way to fabricate the pickup tube to get to where the fluid is in the bottom half of the transfer case. Based on my brief experience in changing the fluid twice it seems to me that the gearing is pretty tight against the case of the unit and there is a very small margin to get the drain tube in there to suck out the fluid.
Yeah... you're right now that I think about it... Probably not going to be a workable solution.

I would have to take the whole T-case out and put in a threaded insert in the bottom. Be a major pain and likely not worth the effort. Too bad they didn't include a drain on this case as it really needs one. This transfer case belongs on a Go-Cart, not a 5k pound vehicle. Crazy bad design if you ask me.
 
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Mazda CX-9
With regard to the ability to pump and filter the transfer case fluid I would imagine the most perplexing part of that would be finding the best way to fabricate the pickup tube to get to where the fluid is in the bottom half of the transfer case. Based on my brief experience in changing the fluid twice it seems to me that the gearing is pretty tight against the case of the unit and there is a very small margin to get the drain tube in there to suck out the fluid.
I just put a drain plug in my 2011 CX9 T-case. It was super easy to be honest. Wish I had done it sooner. Now it will be a cinch to drain and refill since pumping out the old is the hardest part. Filling it up is actually quite easy IMO.

Not sure I will do it or not, but this also gives me the opportunity to add a small 12 volt pump and reservoir to the T-case. Will be thinking about this and whether or not its really worth it.

The reservoir I am considering is this one: https://www.amazon.com/gp/product/B01EC4EBJA/?tag=m20b7-20



It has a breather already on it. So as long as I can find a mounting point where the fluid levels will be the same then this should offer a great solution. I would use a 12volt oil pump to pump the t-case fluid to the reservoir and back through high temp stainless braided lines. The added bonus is that the reservoir has a drain valve on it, so I can just use the drain and pump the old fluid right out of the reservoir. Cost should be under $100 total and would offer a much easier solution to fluid changes.
 
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2014 CX-9 GT
DIY for the first time

Ok, first of all, thank you very much for the starting this topic, it is extremely helpful

Mine: 2014 Mazda CX-9 43K miles , this is our second cx-9. First one was 2008 CX-9, which was totaled by some reckless dude.

Now, For the first time I was doing this job and it was really messy, even I was using the same electric pump shown in the first post. I ended up using entire bottle of RP - a lesson learned

1. The oil came out about 1/3 of qt, and it was not really relly bad (maybe Mazda updated PTU fluid in 2014 and up models. Must to say I have not refreshed the fluid before). It was kind of dark brown, but definitely not sludge and not black and gooey. See the pic
2. The oil definitely has clear burnt smell but not bad
3. Pumping out the oil was not a problem, the electric pump worked like a champ, but putting in was a huge issue.
4. When I was putting in oil, I was using a manual pump with wide (bigger) in and out hoses and it was a mistake. the wide hose makes spilling all over the place as it's not design for putting such small amount of oil.
So I shifted the out hose of the pump to a small one and ended up blowing off it from the pump several time. Apparently, you need to hold the pump and the hose by one hand in order keep in place.
Basically, technique when wide hose inserted into the pump and a small hose out of pump works the best for me, just maintain the pressure and do not rush

IMPORTANT. Based on my experience with motor oils, Royal Purple is average and some time sucky oil. Also reading a tone of threads, I can see people complain it becomes black after 5 thousand or less miles. Which means it's not suitable for the application. Gear Oil should not be that black and gooey after such small amount of miles
Furthermore It was giving me nausea because of the smell of the new oil, just my personal thing.

Because all these factors I will try next time AMSOIL. Additionally, I read somebody was using Some Motorcycle's Heavy Duty oil in his Ford Edge, it's another option.
 

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2010 CX9 Blue
I found a permanent solution to this issue.
I have some cleanup and interior fixes to make on the car and then I'm going to put it on Craigslist and unload it.
 
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CX-9 2013 AWD
I found a permanent solution to this issue.
I have some cleanup and interior fixes to make on the car and then I'm going to put it on Craigslist and unload it.
wait, I don't understand, did you come up with a real permanent solution to transfer case issue, or you're just being sarcastic and solution is to sell the CX-9 ?

if former, please share with members of permanent fix.......

so far the only real fix is to add a drain plug and regularly change out the oil which really isn't that bad once you get used to it,

the real deal killer for me is the inevitable water pump failure, the water pump replacement is way beyond my capabilities and lack of tools, for that reason I'll being unloading it as well, once the water pump seal fails, it'll be very hard to unload it.
 
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2010 CX9 Blue
"or you're just being sarcastic and solution is to sell the CX-9 ?"
The former....not that unhappy with the car overall but at 94k miles on a 2010 I think it's time. Getting out while I'm ahead.
New tires on it and all new front suspension parts from the LCA recall about two weeks ago which included an alignment. I did the brakes not long ago myself so it's in pretty good shape considering. Still runs good and drives great and I wasn't even aware of the water pump issue.
It should have plugs done soon too but I might just skip it.
I'm wheeling a 2015 Highlander now and it's a great, reliable machine but completely uninspiring to drive.
That's OK because to satisfy that fun factor car, the replacement of our CX-9 will be a Jeep Grand Cherokee SRT.
If Mazda decided to grow some balls and build a Mazdaspeed CX9 or even the CX5 with maybe a 300hp turbo4 and AWD, I might be interested, but their new philosophy is another direction. Their cars look great and drive great, but don't have the power I'm looking for anymore.
They are building for a different demographic than myself.
The reliability of the Jeep is my biggest concern but at least I'll have benefits to balance out any hassles that crop up, such as 470hp 6.4L Hemi, amazing brakes, amazing seats, excellent stereo. Test drive hooked me hard. It's a blast.
 
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2014 CX-9 GT
I found a permanent solution to this issue.
I have some cleanup and interior fixes to make on the car and then I'm going to put it on Craigslist and unload it.
No car is perfect in this universe. The 2017 CX-9 has totally new and different powertrain - skyactiv. I was reading, no more Ford parts in it.
This is my second CX-9 and we looked others Honda, Toyota, Hyundai back in 2014 - not our cup of tea.
https://www.youtube.com/watch?v=gl_lV5EUeNg

Anyway, back to topic.
I am using Auto-rx in my engines for years, which is perfect to remove sludge. Did anybody use it in TC?
 
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2014 CX9 Touring, 99 10AE Miata
I have a 2014 touring with 65,000 miles and decided to do this. After a half an hour trip to the store I drove it up on ramps in the front and jackstands on the back so I had plenty of clearance. As you can imagine the transfer case and surrounding exhaust were extremely hot so I had to be very careful. I used the suggested electric pump that I purchased at Northern Tool hooked up to my battery charger and it worked extremely well in extracting the old oil. As someone else suggested perhaps Mazda has change their lubricant or the design of the transfer case or the heat shielding around the exhaust, but whatever the case the used oil was not that bad. I replaced the old oil with Mobile 1 synthetic oil, the same that I put in the transmission and differential of my Miata. It comes in a squeeze bottle so I simply connected it to one of the hoses on the pump and squeezed it in. All in all it was a fairly painless process. I do not feel like I need to do this again for another 30,000 miles. Thanks for the suggestion OP. Now I can sleep better at night!
 
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2014 CX-9 GT
Ok here is my updage after my wife drove 500 miles and i repeated the procedure. The oil came out slightly dark purple almost the same as the original color. I used the same eleftric pump to fill the case and was a right thing to do. There was not a single drop of oil on a floor. I put paper towels on the exaust pipe when the oil started coming out after overflow. That is it, do not use manual pump! This time i used mobil oil, which was on sale at advance auto parts. My personal thought it's better than the RP. Also love design of theirs bottles, as the bottle has measuring indicator which shows how much of oil you have added.
 
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2010 CX9 Blue
No car is perfect in this universe. The 2017 CX-9 has totally new and different powertrain - skyactiv. I was reading, no more Ford parts in it.
This is my second CX-9 and we looked others Honda, Toyota, Hyundai back in 2014 - not our cup of tea.
https://www.youtube.com/watch?v=gl_lV5EUeNg

Anyway, back to topic.
I am using Auto-rx in my engines for years, which is perfect to remove sludge. Did anybody use it in TC?
I know I'm not contributing much to this thread with this info but thanks for the youtube video which compares the new CX9 to the Audi.
We bought a low mile 2016 Q5 3.0T last week and it's hella sweet. The SRT Jeep was a beast, like an offshore race boat on wheels and "not my cup of tea" or my wife's and WAY too expensive for what you get. It is utterly ridiculous frankly.

As for this thread, our 2010 went about 68K as I recall before the PTO puked out the grey goo in my garage and thankfully Mazda repalaced it. If I were the owner of one of these cars and the PTO hadn't blown out yet, I would replace the lube every 50K and use Amsoil, Royal Purple, or Valvoline synthetics. You really shouldn't have to do it at an interval shorter than that.
 
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Mazda CX-9
Well. In spite of changing my case fluid. My transfer case blew up this week. Grinding gears, marbles in a jar, the whole bit. This design is a serious piece of crap. I'm selling my 2011 CX-9 before it dies too, and have to get the 08 fixed before I can do anything. Ordered the case today. What a joke. And Mazda won't do a thing.
 
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CX-9 2013 AWD
Well. In spite of changing my case fluid. My transfer case blew up this week. Grinding gears, marbles in a jar, the whole bit. This design is a serious piece of crap. I'm selling my 2011 CX-9 before it dies too, and have to get the 08 fixed before I can do anything. Ordered the case today. What a joke. And Mazda won't do a thing.
that sucks, failed even after changing the transfer case oil ? I was under the impression because of the low capacity, the transfer case oil was the suspect for the premature failures of the CX-9 transfer case..... I changed it every 20K miles with no issues so far, I'm up to 80,000 miles..... how many miles did the 2008 have before it broke ?

for me, I/m not as concerned about the transfer case , the car can still drive in FWD if I have to, but that water pump issue is a showstopper for me, I don't want to get stuck with a big repair bill, I pan to sell the CX-9 this summer.
 

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