Transmission Service Interval - Aisin Recommendations

I had issues with my tundra when doing my 1st 4 qt drain, and refill using amsoil that was suppose to be compatible with dexronIII. Within the next day the transmission started shifting really weird, and sometimes not at all. Took it to a toyota dealer, as it was still in warranty thinking the transmission was toast. They completely flushed it, and replaced all the dexron III atf. It ran perfect again after that. Never told them I changed the atf before bringing it to them. They still think to this day the original atf just went tapioca for some odd reason.

 

Beyond the act of fluid changes an improvement in filtration is probably even more important to avoid the wear that gearchruncher has described. As i have mentioned i run a magnefine in both the ATf cooler line and the PS return line... Quite a lot of superfine ferrous particles are caught by them as I have found by dissecting used ones (specs say it catches all particles >= 5 microns )



The authors of this article are both automotive engineers with many published SAE articles on automatic transmissions contamination and filtering

https://www.rv.com/archive/tranny-filter-tech/

 

Not me lol right!

 

I can't get past the typo's and poor grammar in that Aisin PDF. That came from the Aisin website?

 

Yeah, I thought the same, almost like it was a fake or a joke!

As others have already pointed out, 1) it's a marketing document intended to help sell fluid, and 2) it doesn't say do a drain and fill, it says "change" the fluid every 20K km. You can take that to mean a drain and fill, but to me, a drain and fill is "dilute with ~30% new fluid." I get how that could give peace of mind, but it's never going to get to 100% fresh fluid.

On my 2012, I did a full change at 90k miles. Dropped the pan and cleaned the magnets, changed the screen and gasket, did a full fluid change from the cooler lines. Fluid was dark and there was a fine black film on the pan surface and magnets, but it still had a bit of color left. Worked fine after the change, no better and no worse. I'm a bit harder on the current truck, so probably change it at 60k miles.

 

Ya, 200k trans fluid. Like going down on a Crack whore, its very dirty.

 

Changing your transmission fluid too often introduces the chance of putting defective fluid in your transmission by a huge multiple. How many bad bottles of WS Fluid out there? Probably thousands and thousands. Keep your changes to a minimum to save your tranny!

 

All the more reason to use Toyota trans fluid

 

Very interesting, the “filter” in our units is just a screen if I remember correctly. Where did you purchase?

 

This is pretty cool, something I knew nothing about before you mentioned it.

$61 Derale 13090 Transmission Filter Kit

https://www.amazon.com/dp/B000CJ25PC

 

And yes, in pan filter is really just a screen of about 100 micron. Since it has to handle the flow requirements of the transmission it cant be restrictive. Since the magnefine fits in the cooler loop it doesn't affect the operation since the cooler line just dumps back into the pan and its only about 8PSI. The magnet is rated to pick up any ferrous (iron/steel) particles >= 5 microns and the paper filter is rated at 35 microns. Having dissected a used one the particles caught by the magnet are so fine I couldn't feel any abrasiveness at all when I rubbed if between my fingers.

Been so long I dont remember exactly where i bought it from. Ordered 3 which has lasted me 8 years based on how i drive.

Old version was a plastic like case that you could unscrew the top when you replaced it and wanted to inspect the magnet etc. New one is a welded seam steel case like the one shown below in my PS return line. For both the ATF and PS installs I used the 3/8 inch versions with bulk Derale 3/8 inch ATF cooler hose and band style spring clamps

$26 Magnefine 3/8" Magnetic Inline Transmission/Power Steering Filter

Amazon.com: Magnefine 3/8" Magnetic Inline Transmission/Power Steering Filter : Automotive

 

very cool, I will definitely install one. Looks like you can do it on the power steering as well.

 

Thats what I did after that...learned my lesson with drain, and refills with toyota dexron III. Never had another tranny issue till I sold it 19 years later.

 

"Quoting from article"

After putting them through a battery of qualification tests, Ford and Chrysler gave them part numbers, but some other OE manufacturers use them as well.
The Ford and Mopar in-house misers didn't go quite so far as letting them install them on all new cars or trucks, but mandate their use when a remanufactured automatic is installed. That prevents contaminants trapped in the cooler from the initial failure, or Type 1 material from the rebuilding process, from killing the new trans.

 

I don’t know.
But I believe a lot of this “when to change it” is going to be based on how you use the truck.
If I’m having to change the fluid in a Tacoma every 12.5k miles, I am probably using the truck outside of its intended use design. Which basically means, it doesn’t matter.

Maybe find a better truck to suit your needs. Or find the problem that’s causing the fluid to fail so soon?

 

I think you answered your first sentence with your with next question.

 

My dad owns a T100. Has 400,000 on it. Transmission was never touched. Works (goes to work carrying load) every day and shifts fine. You'll need some material in the fluid. It's just how they work. 1 drain and fill every 60-100k and you'll be golden.

 

Probably.

I am amazed that there are so many of these shitty trucks still running.

If I’ve learned anything from TW.
It’s that the fluid in it currently, isn’t worth a damn.
And what you put back in it, might or might not be, any better than what you drained out.

I say we drain it all out and invest in a good set of walking shoes.

 

"carcarenut" on youtube seconds your opinion. 60k spill and fills are good enough for me, no need to overcomplicate things.

 

I have read several articles and SAE papers by engineers in regard to automatic transmissions and contamination (debris) and non of them support this. In one it even mentions "No system ever failed from being too clean."

https://www.rv.com/archive/tranny-filter-tech/
https://www.motortrend.com/how-to/129-1002-automatic-transmission-and-power-steering-filters/


Do you have any research supporting your opinion??? I will continue to keep my ATF cool and as clean as possible. Especially with the advent of electronically (solenoid) controlled transmissions. Any ferrous particles will and can home in on these and cause malfunctions and even complete failure.