The NaDM GXs and other BOFs of this era, either never came with a factory cooler or the cooler was deemed not needed (Mike Sweers/Tundra program). Some folks have said, you need to install a cooler as temps cross 200F, others have said its fine. Some have said it stays in line with coolant temps.

So begs the questions can we gather community driven data?

Can owners who are able to access this information kindly share the following:

Fluid type: WS or aftermarket
Regular service: Yes or No
aux cooler: Yes or No
rad: oem or aftermarket
eco light/tc lockout status: yes or no
Transmission Temp: F
Coolant Temp: F
ambient temp: F
altitude: sea level or 10kft
duty: Towing a trailer up a grade or stop an go etc
transmission heat exchanger thermostat pinned open or not: yes or no

Thanks

edit: added exchanger data point, thanks @BenCSVT

 

Suggestion for additional criteria, transmission heat exchanger thermostat pinned open or not

 

Fluid type: 8.5 quarts Aisin ATF-0WS mixed with OEM WS
Regular service: Yes
Aux cooler: Hayden 678
Rad: OEM
Eco light/tc lockout status: On
Transmission Temp: 168
Transmission thermostat: pinned open
Coolant Temp: 187 F
Ambient temp: ~90 deg F
Altitude: Near seal level
Duty: 80 mph interstate, fully stabilized temps after an hour of so of driving



With transmission thermostat unpinned transmission temps stay in the low 190s in the same conditions, so the transmission must have a ~190 degree thermostat

 

Installing a AT cooler can only extend the AT's life, so it depends on your expectations. If you have the time and resources and planning to the keep the GX around for several years, just do it.