2017 Chevrolet Tahoe - Temp question

What temp should a Tahoe transmissions to last longer.

In the normal temperature range indicated on your gauge.
To get the most life out of your:
Transmission, fluid change every 30-50,000 miles. If you carry max loads, or tow near max capacity, get changes at 30,000.
Engine, oil change as indicated for severe service in your owners manual. Note time interval if you don’t reach the mileage.
Cooling system, per owners manual.
Brake system, fluid change every three years.

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My understanding is the only time you really need to worry about transmission temperatures is when towing and/pulling a load up hills, that sort of thing. Because it can cause the transmission to overheat and the fluid to break down more quickly.

That’s kind of an extreme scenario, though. Personally, I don’t worry about transmission fluid temps because I never tow anything. Like Purebred said, keeping the fluid changed regularly will do far more to extend the life of your transmission than anything else.

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If you tow somewhat regularly, it wouldn’t be a bad idea to install an auxiliary transmission cooler, if your Tahoe doesn’t already have one. Below is info on the range for operating temps.

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Keep the transmission temps below 210 degrees for the longest life… and change the fluid and filter regularly. Every 30k is great, 60k is still OK.



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The thermostat to circulate transmission oil to the stand alone cooler in my Mustang doesn’t even open until 185 F. Normal running temp is 190 F. (the car has a gauge) By this chart, my trans has already failed. It hasn’t. But the fluid has been changed twice.

Since many transmissions are cooled by coolers embedded in the radiator, the running temp is going to be around 205 F all the time.

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No Idea of trans fluid temp. It would be similar to radiator temp I assume. If thermostat is 212 degrees is that the trans and radiator temp also?

@Gary33 What is the reason for your question ? Do you know the temperture - did someone say your transmission is running to hot or cold - or what are you wanting to correct. The more information you give will get you much better replies.

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The thermostat temperature is the opening temperature.

The operating temperature can be higher depending on conditions.

Installing a separate transmission cooler prevents the cooling system from effecting the transmission fluid temperatures and the transmission.


Seems clear that trans fluid needs to be warm, but not hot, to work best. Radiator coolers would warm the trans fluid quicker, especially transmissions using lockup convertors that don’t build heat quickly.

A stand alone cooler should have a bypass thermostat to warm the trans up but keep the temp steady like the Mustang’s setup with the 6 speed ZF style trans.

The chart that Tester poster should read “Fluid Life” instead of transmission life vs temp.


My truck just has a transmission fluid temperature gauge that displays ‘normal’ range, never has gone past the halfway position, has a red zone for overheated.
Out of curiosity, switched car gauge to transmission temperature. Did not reach 200 degrees, light use, about 7 miles, 70 degrees weather.