Transmission Temp - What is Too Hot?

[Towin' Tahoe]

Towing my trailer for the first time in my '09 LTZ my transmission temp hit 213 on a long steep grade over the Siskyou Mts. Normal operating temp is listed, high end, at 200 degrees. How much wiggle room is there and at what point should I pull over and stop? Is there a good way to cool it down other than find a downhill grade? BTW, I am towing only 65% of capacity by weight.

 

[GREECO]

This is a great question and one that I’ve also been trying to answer. I’ve read the owner’s manual and it states that the normal operating range is 180-200. I have a brand new 2013 Tahoe with the heavy duty towing package (with the added external cooler) and often hit transmission temperatures in the mid to high 190’s just driving around town not towing. I’ve spoken with 3 different Chevy technicians that have each had a different answer to my question. They never give a specific number that I should be concerned with. They simply tell me that I will get a warning if it gets too hot. I would prefer to pull over and let the engine cool down BEFORE it overheats. The owner’s manual on this vehicle is vague and non-specific. Additionally, the techs don’t seem to know or want to answer specific questions about the vehicle.

Frustrating……

 

[Towin' Tahoe]

Yes, frustrating! Next time I have a service I will see if my techs are any better...but after your experience I'm seriously doubting it. I think my question will be, at what temperature does the transmission overheat light get triggered. That should be somewhere in the tech manuals. We'll see. If I get an answer I'll get back to you.

 

[GREECO]

Over the weekend I had the opportunity to drive my Tahoe in the mountains west of Denver for the first time since I purchased it. The outside air temperature was 78F and after driving for about 20 minutes the transmission temperature hit 211 degrees. There were some light up hill grades but nothing too steep. I was not towing at the time. I wonder how high the temp would have gotten had I been towing.

 

[BlessedHellRide]

I don't have the auxiliary cooler or heavy duty towing package and going from a elevation of 1000 ft above sea level to 9000 ft above temp never went over 193, this was with no trailer and heavy grading, temp was 75 degrees.