2018 CX-5 Transmission fluid change question
- Thread starter Marc4800
- Start date
Depends on how you do it. If you just remove the drain plug, about 3.2 quarts will come out. Never flush a transmission. The proper way is 3x drain and fill. There isn’t much need to drop the pan unless you are having significant shifting issues and want to check if any material is being collected. When you pull the drain plug, if it’s clean, you are good to go.
A "place like Valvoline" --- you're brave. You might do better at a good independent shop with more skilled personnel that are actually mechanics. I would never trust any chain like Jiffy Lube, Valvoline etc with transmission related work. Just my opinion.
Regarding flushes. A special adapter would be needed to flush the transmission and you certainly wouldn't want Valvoline personnel rigging up something to make it work. And, Mazda recommends AGAINST transmission flushes.
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Have a transmission shop who can do it. Gonna go with them.
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- Plano, Texas, USA
Based on many reports here you’d need 3.75 quarts of fresh FZ ATF for a single drain-and-fill. You’d need about 0.75 quart or more if your drop the pan with the filter cartridge change.
Since you have a 2018 CX-5 2.5L NA with cylinder deactivation, your AT is different from previous version with higher ATF capacity (8.5 quarts vs. 8.2 quarts). And you may need a bit more than 3.75 quarts for a single D&F. Follow the proper procedure on ATF level checking to verify.
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- Plano, Texas, USA
Yes you may see only 3.2 quarts of old ATF coming out but you’d still need ~3.75 quarts to refill for a simple ATF drain-and-fill. Many have verified Mazda under-filled the ATF from factory, hence don’t put in the equal amount of old ATF you drained out back in with fresh ATF. Use a good OBDII scan tool to read the ATF temperature (122°F) with engine idling when you check the proper ATF level to verify.
Before you drain, check mark on dipstick. Then drain and refill with same amount and check dipstick. If the level is at the same mark on the dipstick, you are good. Before you start, if you get no or a low reading, then yes it’s under filled. It can’t be considered under filled if the dipstick shows a good read even when it’s cold. On my cars, the reading on the dipstick before I started was about 1/3 up on the box. That’s not underfilled. I might be wrong, but checking it warm is because the fluid expands when hot so you could risk overfilling it.
Edit: I did not realize Mazda was under filling transmissions so replacing what you take out could still leave you low. Mine were a few 100ml low when checked warm.
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- Plano, Texas, USA
Did you check the ATF level at 122°F while the engine was running? If you did with the ATF level at the center marker of the dipstick then you drained 3.2 quarts that just doesn’t add up with people’s experience here. If you checked the ATF level without engine running your level will show much higher on the dipstick.
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You were right. I just checked both my 18 and 19 warmed up and they were on the low side. I added 200ml and that seemed to bring it into the proper range. I’ll check it in a few days to double check.
What’s odd is why we haven’t seen any transmission issues with the fluid being under filled, especially since most people don’t change it ever because Mazda claims it’s a “lifetime” fluid.
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You won't. 122 isn't the normal operating range. As the temp goes up so does the fluid level, trans fluid expands quite a bit with heat. My drain and fill was about 3.25 quarts and everything looked good according to the stick.
Cold or at temp? Mine looked
good cold, but when it was warmed up it was well below the mark on the stick.
2
200955
My 2018 CX 5 AWD took 7 liters as recommended by the dealer. There is no filter to change - it's a very fine screen. I use a clear poly container when I drain, mark the level in the container on the side with a Sharpy and put the exact amount back in. Fluid expansion is already calculated into a cold fill but you'll have to check it on the stick just to be safe.
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- Plano, Texas, USA
Forum member @FerrariF1 originally thought his ATF level from factory was fine while checking the ATF level without engine running on his CX-5 2.5T. Once he rechecked with engine idling, he needed about 600ml (0.635 quart!!!) to bring the ATF level to the Full mark (although the ideal level should be at the middle block area). Mazda under-filled the ATF in his transmission as usual at the factory. That’s why you don’t re-fill the same amount of fresh ATF as drained ATF because the factory fill usually is too low.
He also did an experiment and found the differences on ATF level in different ATF temperatures on his CX-5 with 2.5T:
ATF...Change or not?
But is it really different if you're idling versus just with the car off?? The dip stick doesn't give the same result?
As far as “why we haven’t seen any transmission issues with the fluid being under-filled?” My theory is they’re some transmission problems which could related to this, but only Mazda knows the percentage. The low ATF level must still be within the safety margin which shouldn’t cause too many major issues. But the money saved by ATF under-filling at factory is huge (FZ is expensive)! We still should follow the official procedure to fill up the ATF during the change, which should protecti our transmission better:
The same happened to our rear differential gear oil SG1 (also expensive) on AWD where Mazda severely under-filled it at factory.
Rear Differential Gear Oil SG1 Under-Filled at Factory
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- Plano, Texas, USA
7 liters??? If your dealer did the drain-and-fill for you they’ve made some money from you by exaggerating the ATF amount! You need less than 5 liters even if the dealer dropped the pan to replace the filter cartridge.
No it’s a filter cartridge / strainer there, not a fine screen.
Cut open:
Don’t do that. See my previous post.
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- Plano, Texas, USA
This could be the very cold atmosphere temperature when you did the ATF drain-&-fill?
