Changing CX-9 transfer case gear oil (photos)

2014 Mazda CX-9
I have found my way to this thread due to the burnt oil smell in the passenger cabin issue we are having with our 2014 CX-9 AWD (58900 miles). I crawled under the car and reached up on top of the PTU and found the sludge and the smell. There was a lot of what I can best describe as grease on top of the PTU. I cleaned it all off with a ton of rags and made sure the vent was clear, then I cracked open the fill port on the PTU and no fluid came out. I really was not expecting any. However not having an electric pump I am finding I am not pulling very mush fluid out, much less than those using the electric pump method. I am wondering, Is this an assembly where I could spray in some type of detergent to break down the sludge and then suck it out?. The best I can hope for now is to fill it with the Mobile 75W-140 I purchased and drive it around for a couple hundred miles while I wait for the electric pump to show up via Amazon. If anyone has used a mild detergent before to break down the sludge inside let me know. Also has anyone replaced the PTU unit before and can give an idea of time required to replace working off jack stands.
2010 CX-9 GT AWD
Sorry for digging up an old post.
I really want to know who has highest milage after you replace transfer case oil?
My 2010 with over 106K now but has no sign of burn smell or other engine related problems.
Did I get lucky with my car?
2010 CX-9 GT AWD
I did it today.
I do have floor jack and stands but I went to drove my CX-9 on 4 pieces of 3.5in blocks to make me feeling safer.
Locate and remove transfer case plug was easy and my 8in socket wrench did a good job.
Once plug removed, I can see oil deposition on it as shown in OP picture. I also notice the back of plug is a magnet (to catch metal particles).
I was trying to suck old oil out but nothing. I then decided to pump new in. Let it sit for a while, then pump it out again. Yes, it came out and all black.
I only did twice. 3 pumps in and 2 sucks out. Planing to do more later. I tested transfer case by lift up the car, I release the break slowly and watch for rear wheels to spin. It works, no noise.
Technically, the transfer case has not died on me just yet probably we barely use it. We have less snow in NW WA, we don't tow and no up/down hill driving.
That's why our CX-9's transfer case still survived.
I am planing to change rear differential next day since I don't have right size socket now and getting tired already.
BTW, I used Volvaline oils for transfer case and read differential.
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I have a datapoint for this. Just completed this project today. 2014 CX-9 with 61,000 miles. Yes, I know, long overdue. However, the fluid that came out was OK. It was darker but not black and flowed freely. The plug, as you can see was quite caked up.

There was no evidence of any overflow from the case, no burned smell, and no issues. I noticed that the cat had a heat-shield and maybe that helped prevent from the fluid to be cooked off?

I live in Indiana (no hill driving). My wife was driving this car mostly, city driving and no towing.

Anyway, we plan to keep the car for a while so I think this is a cheap and worthwhile maintenance item.




2013 CX-9 AWD, 2016.5 CX-5 AWD
for 1st gen (2007 thru 2015) CX-9 AWD CX-9 AWD only,

hope this info is useful for some fellow Mazda owners.

the Ford PTU in these videos is the same as in the 1st gen CX-9 AWD


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