Transmission too.... COLD?

[HEMIMANN]

Did a Google AI search... Copied and pasted the resultsView attachment 579588

AI is accurate, eh?

And so did transmissions blow up before they put oil thermostats in them when it was -20F outside? Not where I lived.

170-200 F is NOT A SWEET SPOT. It is accelerated oxidation above 140F. Unless you like to change transmission oil every 25,000 miles, or ruin your trans from deposits.

Ask how us RFE trans owners know.

What is with these newbs coming on here after 20 years and telling lifelong engine builders and tribologists what some coder bro discovered? I mean, wtaf?

 

[Rob2gen]

Atf+4 is designed to run hotter without degradation. Accelerated oxidation doesn't really begin until 200 degrees F... Starts to become a problem above 220.

 

[White six four]

I'm not an expert, but isn't the hottest fluid in the torque converter? The temperature sensor for it I believe is in the pan. I could be wrong on that though. But either way, my thought is that there is always fluid hotter then what the temp sensor actually reads.

 

[HEMIMANN]

Atf+4 is designed to run hotter without degradation. Accelerated oxidation doesn't really begin until 200 degrees F... Starts to become a problem above 220.

No, my dude - ATF+4 is a Group III quasi synthetic with a lot of friction modifier additive.

Stop spewing nonsense here.

 

[Wild one]

Did a Google AI search... Copied and pasted the resultsView attachment 579588

Only the 1500's use coolant to heat the 8 speeds fluid,the cars/Durango's and HD 2500's and up that use the 8 speed don't have the thermal management unit that uses coolant to heat the transmissions fluid. My wifes 1320 Challenger which is Chryslers drag oriented 6.4 Challenger would stay at about 150 to 160 unless you were really hammering on it,and it has a factory high stall convertor in it and is the only 8HP70 that has a factory transmission brake for drag racing.So to me that means even Chrysler runs the 8 speeds a bit cooler in their hi-po applications or heavy duty truck applications

 

[Rob2gen]

So are you saying that atf+4 is not a full synthetic fluid? Yes, it's a Group 3 base oil that is highly refined, then an additive package is added to it. It is the textbook definition of full synthetic . The fluid is designed to flow at extremely low temperatures, is highly refined, designed specifically for MOPAR transmissions, and not break down at higher temperatures.

The OP has questions about fluid temps while driving in colder weather/climate. I'm not addressing the clunk he senses as it could be as simple as fuel sloshing in his gas tank or even something loose in his pickup bed, which has already been addressed.

The information I have provided is intended to be helpful, insightful, and not misleading.