2020 Transmission Drain and Fill

Doesn't matter

 

If my understanding is correct, the ATF temp for fluid level checking is lower than the opening temp threshold for the cooler. You pin it open so you’re flowing the lukewarm fluid through the system because that is the right temp for the fluid thermal expansion to be where Toyota determined the proper level.

Big dumb round numbers:
Fluid temp for level checking is 110°
Thermostat opens at 170°

You need to check at the ~110°. But the thermostat has to be open to check level correctly. Pinning it open is the only way to do all of this.


Temp or thermostat means nothing for a fluid drain or fill. Just checking.

 

Rock & roll, thanks

 

Wouldn't make a difference, either way when the truck is off all the fluid is drained back into the pan whether it's pinned or not, it's only when the truck is running that if the thermostat is not pinned the fluid won't flow to the the cooler until the temp reaches around 180.

 

Got started on my AT cooler install . I realized after the pic that I had the spacer installed wrong but it's correct now

 

Did a drain and fill in my 2020 today. Super smooth. Thanks for the good info. Did not need to jump my OBD2 port.

 

Did a drain and fill on my 2016 today. I replaced both the drain and the check plug, the 5mm allen hex stripped and removed it with vice grips and used my Fusion app for fluid temp.