Transmission fluid interval 2019 Corolla will dump and replace cause damage at 22,000?

[doublebase]

You forget something. A brand new lock up torque converter has the clutches operating optimal from the factory. But as soon as you start using it, the clutch material starts to wear, wear particles from the clutch which gets suspended in the ATF.

Over the long term, when there clutch is worn enough, it will start shuddering on a "clean" fluid if you overdo the ATF as suggested above. Then you have to start adding stuff like Lubegard additives as a band-aid to replacing the torque converter, so lubegard makes some money on this.

We’re talking simple spill and fills here - you’re only replacing 2-3 quarts out of a 7-8 quart system. It’s not like the vehicle is hooked up to transmission exchange machine with a cleaner added. It’s just a simple regimen of changing out 2-3 quarts and replenishing the fluid. If anything bad happens from doing this ^^^, you have bigger issues with your transmission. IMO.

I‘ve done simple drain and fills on all my vehicles since day one of ownership. I owned a 1999 Honda Accord (since new) - and those were the problem transmissions...class action suites, extended warranty programs - and by doing simple drain and fills every year (15,000-25,000 miles), I never had a single missed shift or slip, in the nearly 300,000 miles I owned it, out of a transmission known to fail between 50,000-120,000 miles.

I understand what you’re saying...the clutch material that’s suspended in the fluid can add friction properties for the clutch packs. But changing out a small amount of fluid every year is such a gradual thing that allows the fluid/clutches to adjust. IMO. Now, doing an entire exchange of brand new fluid on an older transmission that has never been serviced?? Yeah, there is clutch material built up in the nooks and crannies of a valve body, and that new fluid could potentially free that up and send that material to a valve or solenoid and lock it up. Then you’re in trouble. Or that new fluid could reduce the friction properties for the clutch packs. I agree with that.

 

[doublebase]

Apologies to all. I do not want to dispense inaccurate information.

Ha! I was just following a 2019+ model Corolla HB on the freeway.

My 2019 Lexus 250h and my current 2022 CorollaCross both use the same fluid.

I forgot that the 2019 Corolla sedan has a regular CVT, as clearly stated by OP.

The take is: use correct, genuine factory fluid, even if it is the basic, average quality WS.

Aisin makes a WS fluid for Toyota’s that is “better” than the WS fluid (and Aisin makes the transmissions for Toyota). And when I say better, I mean its synthetic (which WS is not). And I believe there are other brands now that formulate exclusively for the Toyota WS specs, whereas for 10-15 years we only had the Toyota WS, or universal multi-vehicle substitutes.

It doesn’t matter to me, I’ve used WS for over a decade now with no issues (probably because I do drain and fills regularly), but the Toyota WS fluid changes color and turns dark very very quickly. I’ve seen the fluid BLACK in less than 50,000 miles. I‘m not saying the fluid is bad at 50,000 miles, I’m saying it turns dark very quickly - someone has a YouTube video of the fluid darkening in just sunlight, going from red to dark purple in no time. Again, I’m not saying it’s bad fluid, I’m saying the dye drops out very quickly and appears as if the fluid is burnt (when it probably isn’t). I’ll never forget the day I bought a used Lexus LS460 with 70,000 miles on it - first thing I did was a tranny service - the fluid was blacker than oil. I’m standing there with a few techs and we‘re all looking at each other like, uh oh...and it was fine. Drove it a 100,000 miles with no issue.

 

[DGXR]

I would wait until around 30-40k miles before servicing the transmission. You can check the fluid level without doing a full service.