Transmission fluid change without filter replacement

There must be a reason why car manufactures started to use silicon sealant instead of traditional cork gasket on ATF pan. Applying silicon will be more time consuming, in theory it’s not worth it for car manufactures to do it. Cork gasket on ATF pan is horrible and will start to leak in a short period of time. Newer synthetic rubber gasket should be better, but still why it’s not been used by the factory?
Might as well perma-seal the pan to the transmission if there’s no service schedule. Less chance of a leak during the life of the vehicle?
 
Just did my new to me 2013 CX-5 with 90,000 on it yesterday. Dropped the pan, cleaned the magnet, replaced the old filter with a new Wix part number WL10379. The Wix comes with a rubber gasket, so you don't have to worry about letting the RTV set.
Good to know. This definitely gives us a good alternative to drop the ATF pan, and have confidence putting it back with ease by a synthetic rubber gasket.

Because I dropped the pan and filter, it changes a lot more fluid than a simple drain and fill. Normal drain and fills are about 3 quarts, the filter drop is about 4.5 quarts of Mazda Type FZ and ONLY MAZDA FZ!!! Don't be tempted to use generic parts store ATF. I promise, it ain't the same stuff. Hell, the FZ is even blue!
This information is contradicted to the quantity reported by many others. Most say drain-and-fill takes about 3.75 quarts of the ATF.

Dropping the pan takes about 4.2~4.5 quarts as quite a bit of ATF would stay in the ATF pan which can’t get drained out.
 
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Might as well perms-seal the pan to the transmission if there’s no service schedule. Less chance of a leak during the life of the vehicle?
Makes sense! Like engine oil pan and timing chain cover.
 
There must be a reason why car manufactures started to use silicon sealant instead of traditional cork gasket on ATF pan. Applying silicon will be more time consuming, in theory it’s not worth it for car manufactures to do it. Cork gasket on ATF pan is horrible and will start to leak in a short period of time. Newer synthetic rubber gasket should be better, but still why it’s not been used by the factory?
That WIX gasket looks to be rubber/silicon
 
Perhaps it is quicker and easier to have a robot apply the sealer than deal with a gasket that has to be positioned correctly for the bolt holes to line up during assembly
 
Perhaps it is quicker and easier to have a robot apply the sealer than deal with a gasket that has to be positioned correctly for the bolt holes to line up during assembly
If I were a robot, I’d prefer the job positioning a gasket than apply the silicon sealant, as the former is a lot easiler ⋯ :whistle:
 
I'd like to see how much sludge is in the pan the 2nd time somebody drops their pan. Is there any reason to think that the precipitated sludge doesn't just stay put. Likewise, is more stuff accumulating in the filter, or is the original stuff just stuck on the safe side?
 
I'd like to see how much sludge is in the pan the 2nd time somebody drops their pan. Is there any reason to think that the precipitated sludge doesn't just stay put. Likewise, is more stuff accumulating in the filter, or is the original stuff just stuck on the safe side?
I believe most of time the crud and sludge should stick on the magnetic and pan until there’re too much. Here is Digbicks1234’s observation on crud and metal shavings with plenty of pictures when he dropped the ATF pan of his 2016.5 CX-5 at 64.4K miles:

2016.5 CX-5 Transmission fluid change questions


“My observations:
  1. The magnet was extremely dirty with so much crud and metal shavings on there, that I actually think I should've dropped the pan sooner. Honestly, this really depends on how you drive but I did drive pretty aggressively in the beginning and then moderately-aggressive afterwards. The car has 64.4k miles so far.
  2. I cut open the filter and I did see some metal shavings inside the filter. Don't know if this is a good thing or not but I'm still waiting for my oil analysis to be processed. I'm not sure if I'll use Wix again for an oil analysis, seems like their customer service isn't so great but for $10-11, can't really ask for much.”
Magnet (Gunk):
08224A30-C48F-4EAB-A406-722C1F4F5200.png

644C6388-6FB1-452A-8A23-55F98A9407F8.png


Magnet (Clean):
B2371E19-B59B-4EBD-8849-9C84DD14EA21.png


Filter Cut Open with metal shavings:
E108BCCC-32B4-43AC-826F-F861803309F1.png


“Yes, the magnet has a ton of shavings. Pretty much the whole thing was caked with it. There was quite a bit of ATF, maybe around 0.5 - 0.8 quarts. The amount of residue would depend but in my case, there was quite a bit of residue that I had to clean up with a number of paper towels:”
7A0611AE-1B77-48CA-AD28-5B3826978881.png
 
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Just did second of 3 ATF drain and refills. First I ran the engine to get the ATF temp to 122 deg. Checked the level and it was a bit under the mark on the dipstick. Drained just over 3 1/2 quarts, probably 3.6 to 3.65 quarts. Then I filled with 3.75 quarts of fresh ATF FZ this time. I left 8 ounces of fluid in the 4th bottle. Ran the engine again to get the temp to 122, checked it, and the fluid appeared to be squarely on the mark.

Last drain and refill in 2 weeks, just in time for a road trip on Feb 11th.
 
I believe most of time the crud and sludge should stick on the magnetic and pan until there’re too much. Here is Digbicks1234’s observation on crud and metal shavings with plenty of pictures when he dropped the ATF pan of his 2016.5 CX-5 at 64.4 miles:

2016.5 CX-5 Transmission fluid change questions


“My observations:
  1. The magnet was extremely dirty with so much crud and metal shavings on there, that I actually think I should've dropped the pan sooner. Honestly, this really depends on how you drive but I did drive pretty aggressively in the beginning and then moderately-aggressive afterwards. The car has 64.4k miles so far.
  2. I cut open the filter and I did see some metal shavings inside the filter. Don't know if this is a good thing or not but I'm still waiting for my oil analysis to be processed. I'm not sure if I'll use Wix again for an oil analysis, seems like their customer service isn't so great but for $10-11, can't really ask for much.”
Magnet (Gunk):
View attachment 284886
View attachment 284887

Magnet (Clean):
View attachment 284888

Filter Cut Open with metal shavings:
View attachment 284889

“Yes, the magnet has a ton of shavings. Pretty much the whole thing was caked with it. There was quite a bit of ATF, maybe around 0.5 - 0.8 quarts. The amount of residue would depend but in my case, there was quite a bit of residue that I had to clean up with a number of paper towels:”
View attachment 284885

Did you mean 64.4k miles and not 64.4 miles?
 
so when is it recommended to change the atf fluid,miles/years?
tnx
Mazda recommends nothing. I personally would do drain-and-fill at 50K ~ 60K miles. May consider to drop the pan with filter cartridge replacement.
 
Unless you're having shifting problems I don't really see a reason to do it before 100K miles. No matter when you do it, the first time will always show high levels of metals in the fluid during a UOA, and there will be lots of metal shavings on the magnet, but most of that is from the initial break-in when the gearbox was brand new.

I've tossed around the idea of using a syringe to pull a sample of fluid out of the dipstick hole, maybe a couple weeks after my 3rd drain and refill, just to see the difference in amount of metal shavings in the fluid, out of curiosity.
 
my car is at30k miles,once or twice a week im doind 100mph for 15-20 minuts,sometimes more,
thats why i thought its good to thoughts?
tnx
 
On all of my Mazda's, the interval I use is this:

30k miles: drain and fill
60k: drain, drop pan, change filter, clean magnet, fill
90k: drain and fill
120k: drain, drop pan, change filter, clean magnet, fill

You get the idea.
 
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