Guide: 2016~2021 CX-9 DIY Transmission Fluid Drain and Fill + Filter Change

[alekii_405]

Chiming in to report that mine was also low by around .75 qts (estimated 122F temperature) so I agree that you can't just put back what came out. I decided to use Castrol Synthetic Transmax ATF based on this thread, given I had some laying around. At 80 k miles, it's a night and day difference, with no more slipping and general rough shifting. However, time will tell if this was foolish. I plan to do a full filter change and OP drop when I do major service at 100k miles.

Shame on Mazda for making such an important task needlessly difficult. The trans oil was absolutely toast.

 

[PTguy]

Is there an easy way to unplug a power wire to the fan so it can't operate? Don't forget to plug it back in when you're done.

 

[N7turbo]

Chiming in to report that mine was also low by around .75 qts (estimated 122F temperature) so I agree that you can't just put back what came out. I decided to use Castrol Synthetic Transmax ATF based on this thread, given I had some laying around.

Universal doesn't mean optimal, to me. Hopefully .75 qts doesn't hurt anything.

 

[Unistang]

Just completed this. With an aftermarket intake, it makes checking the level so much easier. I think the one step missing from the initial instructions is to move the main trans wire loom out of the way to access the dipstick. Its only two push clips that come out fairly easily. Once that was done this was really easy. I got out 3.75 initially and drained and filled twice with Amsoil sig FE. At the end, when setting the level I realized that the factory level was about a half quart low so make sure you set the level after doing this as its a critical step. A little trick to filling these initially is on the final drain and fill to only add about 3.5qts. My engine was already hot and when it was started the trans temp quickly climbed to about 160-170 degrees when mixing with the existing fluid. From there I pulled the dip stick and kept adding until it was at the top of the range. Once everything cooled down, I rechecked at 122 degrees and it was smack in the middle where it should be. My car only had 40k on it and the fluid had seen better days. I planned on draining and filling 3 times but after the first replacement, the fluid was already so red that I just did 2. Now that I have better fluid in there, I'll probably do this every 50k and not blink an eye. Hopefully this helps someone. I've done drain and fills on many transmissions and this one is definitely not that bad.

 

[N7turbo]

I would be worried about transmission-related warranty claims (if one were ever needed) and a dealership seeing red fluid in my transmission.

 

[Unistang]

I’ve seen blue fluid before with my Sequoia. This stuff was either in terrible condition or it was amber. The dealer will have to prove that the fluid caused the failure. Of all the Amsoil lubricants, their sig series tranny fluid is next level. Every car I’ve used this stuff in benefits immediately but it’s pricey.

 

[Bigsteeder]

Edit
Just read that an OBDII might be needed to read the ATF temp at 122 deg F.
Edit
Or is driving it to warm up the coolant temp gauge on the instrument cluster like 30 mins drive is enough?

Has anyone found a way to know the transmission temp. Basically to accurately read the trans dipstick?

I know this is an old thread, but I just bought an OTOFIX D1 Lite Bidirectional Scan Tool on Amazon for $300 that allows me to plug into the OBDII and get live data, mainly I wanted it to show the transmission fluid temperature specifically to do the fluid swap and you want it to be at 122*F per manufactures specs. Otofix is made by Autel without paying quite a bit more for the name. I figured $300 for a good scan tool that can give me live data like this is better than not putting in the correct amount of ATF and ruining a transmission worth thousands.

 

[Bigsteeder]

The light turns off at 131°F coolant temp. No idea what that relates to in the ATF or oil temps though.

Not a good guide to go by unfortunately. When I ran my Otofix that shows engine temperature and transmission temperature, they aren't good to go off of and my guess is that it would vary also depending on weather and how long you have been running your car, etc. So when my transmission hit 122*F, where you want it to be for the ATF levels, my engine coolant temp was already up to 163.4*F. See picture below.

 

[Unistang]

All,

Has anyone experienced more than unusual venting of the transmission after a fluid change? Its not venting fluid but definitely fumes. I get a smell in the car every so often still and was seeing if this will dissipate after some time and this is normal. Even if this was related to a spill it would have been gone by now, as I'm at about 500 miles post flush. There are no leaks, anywhere (not the dip, not the pan, not the plug, anywhere) and the fluid is spot on in the middle mark at 122 degrees (checked this 3 times now). I will say that the factory fill was low by about 1/4 of a quart and I'm starting to wonder if that was by design for this very reason and maybe its aerating a bit because I corrected the level. I've never had this issue on any other car that I've done this to (Nissan, Toyota, older Mazda). Appreciate any help in advance.

 

[Unistang]

All,

Has anyone experienced more than unusual venting of the transmission after a fluid change? Its not venting fluid but definitely fumes. I get a smell in the car every so often still and was seeing if this will dissipate after some time and this is normal. Even if this was related to a spill it would have been gone by now, as I'm at about 500 miles post flush. There are no leaks, anywhere (not the dip, not the pan, not the plug, anywhere) and the fluid is spot on in the middle mark at 122 degrees (checked this 3 times now). I will say that the factory fill was low by about 1/4 of a quart and I'm starting to wonder if that was by design for this very reason and maybe its aerating a bit because I corrected the level. I've never had this issue on any other car that I've done this to (Nissan, Toyota, older Mazda). Appreciate any help in advance.

Figured this out. In short, don't buy a catch can from Corksport. The oil fume venting was not worth the benefit. Felt like a well made product but not a sealed system like they advertise. Had me chasing my tail for months. No fumes now after removal and car runs great.

 

[speed3chris1]

When I had my 2016 I put the Cork Sport Oil Catch Can on and had the same problem. Cork sport puts out great products but this is not one of them.

 

[N7turbo]

I have not yet heard of an oil catch can improving things on a Skyactiv engine. I'd leave well enough alone.

 

[Veroguy]

Items needs:
1) 8MM Hex Bit
2) Drain plug gasket ( 9956-41-400)
2) 10MM socket
3) Phillips head screwdriver
4) Loooong skinny funnel
5) Atf Type-Fz - Mazda (0000-FZ-113E-01)
Approx 5-6qt per drain

I warm the vehicle to operating temperature to get the fluid circulated before draining for 2hr. Total capacity should be 8.5qt and I drained 5qt. This is highly YMMV. Please do take into account that fluid will expand with heat.

Before you start, you can consider the following:
The fill plug sits VERY VERY low so you have two options to fill:
A) To avoid removing the airbox, you can go under the car and use a fluid pump
B) Remove the airbox and get a loooooooooooong funnel. To get an idea of how long, you can refer to my picture. With the fully extended spout + the long funnel combo, the top of the funnel was at the level of the framerail.

Steps:
1) Unscrew hose clamp (see attached picture) and decouple the intake hose from air box
2) Remove 2 10MM bolt that hold the snorkel
Be mindful of the MAF sensor harness!!!
3) Pull the entire airbox/snorkel unit upward
You should have enough space to rotate the unit away. Tape the intake hose shut to prevent dust from entering.
4) Locate the fill hole, and remove a 10MM bolt holding down the plastic dipstick
The dry o-ring on the dipstick was stubborn, so I twisted the dipstick back and forth and used a tiny bit of force to pull it out. BE CAREFUL NOT TO KNOCK ANY DUST OR DEBRIS into the transmission fill hole.
5) Use 8MM hex bit to remove drain plug and replace washer
6) Let the fluid cool down to retract and measure
7) Use a loooong funnel to replenish the same amount that was drained out

I just changed my transmission filter and fluid in my 2020 CX9 with 53,000 miles. Amazing how "lifetime" transmission fluid looks after 53K! Almost black in color, and a fair amount of sludge in the pan.

I bought the aftermarket filter, which came with a gasket. There was no gasket on the factory transmission pan, just sealant. I tried using the gasket, but wasn't happy with it, because as careful as I tried tightening down the pan evenly, the gasket would bulge out in several spots. Finally, I just took it off and then used Permatex Transmission Sealant, which worked great.

Note that the pan bolts are to be torqued at 12 ft/lbs. Be careful threading these in and not to use an impact wrench while reinstalling, as the aluminum block and threads strip very easily.

Best place I found for Mazda Transmission fluid price wise, was on www.mazdaswag.com. At $12.35 per quart. Did a fair amount of research, and despite using other aftermarket fluids, decided to spend the extra for the Mazda brand. 0000-FZ-113E-01 - Atf Type Fz - Mazda Swag

After draining, I had almost five quarts, which I refilled with. Note, checking on the level depends on the temperature of the fluid, which is marked on the dipstick.