ATF...Change or not?

[AVC]

Yep, that's my point with the OEM procedure--out of reach for the avg DIY. You either have to check it stone cold (same temp for drained and replacement fluid) or check it at full operating temp (running or no), for which Mazda doesn't post a dip stick reading, to my knowledge.

 

[theblooms]

Just done ATF on my 2017 CX5 yesterday (removed pan- replaced filter---applied RTV again)

Draining for a few hours but only put back about 4.1-4.2L transmission fluid. Is this normal?

Then should I do it again after a while? From the above chart the total amount is like 7.8L- 8L

Also my OBD tool doesn't show the ATF temp, I started the car and running about 10 mins, when I check the level looks fine. So if temp low will the level high or low?

Most of the fluid is in the torque converter, which only certain cars can be drained. Ours isn't one of them. So you did fine.

 

[theblooms]

Yep, that's my point with the OEM procedure--out of reach for the avg DIY.

I couldn't disagree more. But whatever.

 

[AVC]

So if you don't have a scan tool that can access specific Mazda PID for trans fluid temp, how do you accurately determine the magic 122F?

 

[Yo'sDad]

So if you don't have a scan tool that can access specific Mazda PID for trans fluid temp, how do you accurately determine the magic 122F?

I think too much is made of the magic temp. Get it warmed up, idling in park and adjust the level using the dipstick, add some or suck some out until you get it close to the mark. Don't make this rocket surgery. Just me feeling.

 

[yrwei52]

Just done ATF on my 2017 CX5 yesterday (removed pan- replaced filter---applied RTV again)

Draining for a few hours but only put back about 4.1-4.2L transmission fluid. Is this normal?

Then should I do it again after a while? From the above chart the total amount is like 7.8L- 8L

Also my OBD tool doesn't show the ATF temp, I started the car and running about 10 mins, when I check the level looks fine. So if temp low will the level high or low?

You can only drain about a half of total ATF capacity athose in the torque converter and some in the valve body can’t get drained. Usually 3.75 quarts (room temperature) is for a simple drain-and-fill. 4.1 ~ 4.2L / 4.3 ~ 4.4 quarts to refill with the filter change seems to be on the low side from the reports we’ve seen.

Did you keep the engine idling when you check the ATF level? If you didn’t, the ATF level will be higher, hence the low-fill.

You should get something like Forscan live data tool recommended here by @edmaz for more accurate ATF temperature readout:

Perhaps do both and see how much they differ? The ATF temp sensor is located inside of the transaxle valve body, so it's just a guess as to how close those three temps would be at the 122ºF target checking point.

Just an FYI that, if you have a Windows laptop, you can get the Forscan live data tool up and running on it for as little as $20. Forscan currently offers a free download of their software for Windows, and you can buy an inexpensive OBD adapter to read TFT (and a whole lot more as well). The Forscan doc states that they no longer support the lower-priced adapters, however they still work just fine for the simple stuff. This is a very easy and inexpensive way to get TFT the way the manual says to do it. But as always, your vehicle your choice.

Guide ATF Drain/Fill

Anyone found an OBD2 phone app that will read transmission fluid temp?

Here @FerrariF1 did an experiment and found the differences on ATF level in different ATF temperatures on his CX-5 with 2.5T:

Since we can only drain a half of the ATF, many would do 3X ATF changes to get about 87.5% of fresh ATF in transmission. Yes you can do 2 additional simple drain-and-fills with some miles in between. And check any possible leaks while you’re there.

 

[sinistriel@]

I try and stay out of these back and forth threads like this because it can become contentious. The reason 122* is specified is because over 100* FZ begins to thin and expand rapidly. FZ actually expands a fair amount when its hot, when its too full the fluid gets whipped up by the planets and aerates, when that happens the pump will cavitate and start pushing air through the transmission. This has two big issues. It stops lube going getting to critical areas and uses air to start to apply the clutch sets. Air has nowhere near the amount of holding power that a fluid does in the same circuit, this causes premature clutch failure. Too low of a fluid level and you'll also suck air and run into line pressure issues again. At around 122* the fluid while running will be within the safe zone to adjust fluid level one way or the other. The attached picture shows in relation to the internal points of the trans where the fluid is in relation to the level on the dipstick.

 

[yrwei52]

Yep, that's my point with the OEM procedure--out of reach for the avg DIY. You either have to check it stone cold (same temp for drained and replacement fluid) or check it at full operating temp (running or no), for which Mazda doesn't post a dip stick reading, to my knowledge.

Yep as far as I know changing the ATF on Honda’s and Toyota’s doesn’t need to know the specific ATF temperature.

I’d agree that we can simply refill the same amount drained at the room temperature and be done with it. The only problem to me is most checked have found the ATF is a bit too low from factory. That’s why people shouldn’t use the ATF amount drained as the reference to fill the same amount of fresh ATF back into the transmission. They’d under-fill the transmission again.

Once been verified the correct ATF level at 122°F with the engine idling, we can do the subsequent easy ATF changes refilling the same amount as drained.

 

[AVC]

As I wrote, even if the factory fill was somewhat lower than "nominal", it really is irrelevant unless there were ALSO performance issues also associated with it. You can (and I do) just reference whatever the factory fill level was at room temp and that forever becomes the (my) reference.

It's wool gathering to insist on a perfection that Mazda didn't impose on their own manufacturing, especially if there are (probably) ZERO reported incidents regarding transmission woes because of "low factory fill".

I even question whether the reported "low levels" were actually, technically low to Mazda's specification, because DIY's checked at low ambient temps, where Mazda is entirely silent as to where that ought to show up on the dip stick.

 

[yrwei52]

⋯
I even question whether the reported "low levels" were actually, technically low to Mazda's specification, because DIY's checked at low ambient temps, where Mazda is entirely silent as to where that ought to show up on the dip stick.

Those reported low factory fill on ATF are creditable members here who had definitely followed the official procedure from Mazda Workshop Manual making sure the ATF temperature is at 122°F and the engine is idling.

Fluid color was about the same color as ColoradoDriver's. It was obviously brown on dipstick too. I remember checking it at half mileage and it was visually clearer at that time.

Experience on mine:

Drained amount: 3 quarts & 13 fl oz (3.4 quarts)

Refill amount: 3 quarts & 23 fl oz (~3.72 quart)

While my AT temperature was at 122F my coolant was around 160F from a cold start scenario.

I agree.... all the measuring is cumbersome but now that I have a known good fill amount subsequent changes will be easy.

- Removed bottom splash shields
- I checked dipstick from bottom
- I filled from the top with long reach funnel
- I didn't need to disconnect anything up top.
- Loosened fill plug from top but removed from bottom. One could as seen posts above remove from bottom as well.
- Tightened the fill plug to in-lb with torque wrench from top

You guys were right, I checked the ATF while idling and it was low. The ATF was at around 25-30 C (77-86 F). I added 600ml and it came up to the middle of the 2 lines, so perfect. I don't think ATF expansion is that great that I need to check at 122F, and I'm guessing if I were to check at 122F it would be closer to the top line.

I also changed the rear diff and front transfer case, and they both took about 0.5L each. Not too complicated.

Update: I warmed up the transmission fluid to 51C / 123F and re-checked level (car idling, level surface) and it was just below the Full line. MS Paint artwork attached.

Summary: added 600ml to factory fluid to bring it up to full level. I did not drain and fill since car has 30K km / 18K miles.

View attachment 320245

 

[AVC]

OK, I concede if that's true. I still maintain the prior point on pragmatic relevance. In other words; so it was low. To what consequence (other than an academic principle)?

 

[yrwei52]

OK, I concede if that's true. I still maintain the prior point on pragmatic relevance. In other words; so it was low. To what consequence (other than an academic principle)?

Only Mazda knows the consequences if the ATF level isn’t within the range of the dipstick. We can only follow as best as we can from Mazda’s official procedures making sure they’re within the specs. But even that, Mazda has been given conflict informations to check the fluid levels, such as the gear lube level at the rear differential.

 

[Kedis82ZE8]

There is a line on the dipstick and Forscan or OBDLink or Fusion are known working OBD setups to read the AT temp PID.

It was thought years ago there wasn't one and it was only reading coolant temp.

Anyone found an OBD2 phone app that will read transmission fluid temp?

Still looking but leaning toward there is something from the personal data I have observed in my own vehicle and some of the FSM data. I can't say definitively either way though at this point. If it is there it isn't a standalone sensor and like I said before part of the valve body or that...

mazdas247.com

 

[ruthrj]

Quick question only for those of you who have personally done the 'drop the pan' version of an ATF fluid change. I'm looking for actual user info, not speculation or anything else please.
Did you do the gasket approach or the sealer (no gasket) approach. Did you get leaks or 100 percent seal. That is it. If you used sealant, which brand did you use. Thank, Tom

RTV sealant. No leaks 100% seal. Mazda OEM gray silicone

 

[moonj]

You can only drain about a half of total ATF capacity athose in the torque converter and some in the valve body can’t get drained. Usually 3.75 quarts (room temperature) is for a simple drain-and-fill. 4.1 ~ 4.2L / 4.3 ~ 4.4 quarts to refill with the filter change seems to be on the low side from the reports we’ve seen.

Did you keep the engine idling when you check the ATF level? If you didn’t, the ATF level will be higher, hence the low-fill.

You should get something like Forscan live data tool recommended here by @edmaz for more accurate ATF temperature readout:



Guide ATF Drain/Fill

Anyone found an OBD2 phone app that will read transmission fluid temp?

Here @FerrariF1 did an experiment and found the differences on ATF level in different ATF temperatures on his CX-5 with 2.5T:

View attachment 321005
Since we can only drain a half of the ATF, many would do 3X ATF changes to get about 87.5% of fresh ATF in transmission. Yes you can do 2 additional simple drain-and-fills with some miles in between. And check any possible leaks while you’re there.

I think then probably fine for me.
I shutoff the car when I checked the level showing almost to the Full position (upper line)
I checked again this morning with cold temp and it's about to the mid level.

Thanks! Will plan do a drain and fill next year. (85000KM now)

 

[Conrad 16.5]

Just done ATF on my 2017 CX5 yesterday (removed pan- replaced filter---applied RTV again)

Draining for a few hours but only put back about 4.1-4.2L transmission fluid. Is this normal?

Then should I do it again after a while? From the above chart the total amount is like 7.8L- 8L

Also my OBD tool doesn't show the ATF temp, I started the car and running about 10 mins, when I check the level looks fine. So if temp low will the level high or low?

Most things in this world expand as they're heated, so....

 

[yrwei52]

I think then probably fine for me.
I shutoff the car when I checked the level showing almost to the Full position (upper line)
I checked again this morning with cold temp and it's about to the mid level.

Thanks! Will plan do a drain and fill next year. (85000KM now)

Can you try to check the ATF level with the engine idling? I believe that would affect the level much more than the temperature. @FerrariF1’s diagram is based on the measurement with engine running. He added 600ml to the factory fill to reach the level showed.

Most do the next drain-and-fill within a week or 2 of driving. I personally wouldn’t wait that long for the 2nd and the 3rd drain-and-fill, especially your first drain-drop the pan-and-fill seems to be having a questionable fill amount as most reports for pan drop is at least 4.75 quarts, one additional quart than a simple drain-and-fill of 3.75 quarts. Some even reported close to 6 quarts.

 

[ruthrj]

Most things in this world expand as they're heated, so....

Water going from solid to liquid being the exception sorry, had to liven up the mood in here a bit

 

[moonj]

Can you try to check the ATF level with the engine idling? I believe that would affect the level much more than the temperature. @FerrariF1’s diagram is based on the measurement with engine running. He added 600ml to the factory fill to reach the level showed.

Most do the next drain-and-fill within a week or 2 of driving. I personally wouldn’t wait that long for the 2nd and the 3rd drain-and-fill, especially your first drain-drop the pan-and-fill seems to be having a questionable fill amount as most reports for pan drop is at least 4.75 quarts, one additional quart than a simple drain-and-fill of 3.75 quarts. Some even reported close to 6 quarts.

Thank you!
I put the car idling then the level goes below the lower mark. I fill more ATF in. I have 1L bottle and the 5th one left about 600ml, so I put in about 4.4L---should be about 4.65 quarts.

PS:
I removed the airbox so I have to use OBD to clear some codes after I put everything back in.
I will do another drain and fill in a few weeks then.

 

[yrwei52]

Thank you!
I put the car idling then the level goes below the lower mark. I fill more ATF in. I have 1L bottle and the 5th one left about 600ml, so I put in about 4.4L---should be about 4.65 quarts.

PS:
I removed the airbox so I have to use OBD to clear some codes after I put everything back in.
I will do another drain and fill in a few weeks then.

Your next 2 simple drain-and-fill should be a lot easier and don’t need to put the under cover back until you complete the 3X D&F.

The ATF amount for a simple D&F should be more consistent from all the reports here, 3.75 quarts at room temperature if you drain the ATF long enough.