2016 Yukon XL Needs New Transmission - Not Happy

[Rygrego]

Start changing the fluid on the new one every 40K. Consider dumping the thermostat attached to the side of the transmission too, no need for it to run at 195 all the time.

The updated temperature is 154 with new thermostat.

 

[OR VietVet]

My 2005 transmission runs at 135 to 150 at all times except for when I run it hard and then I have seen as high as 165 to 175.

 

[JMH1980]

I have a 2016 Denali and so do two friends of mine. All three of us have had the transmission shutter issue which is corrected by replacing the fluid. I would be very concerned that an unfamiliar or inexperienced "technician" might not know the cause and pull the plug and find metal. I have seen a lot of transmissions that had metal filings in the pan but were perfectly good. The shutter is very pronounced and could be mistaken for an internal failure. It is hard to believe that changing to a different fluid would make a difference but it clearly does. A second opinion might be a good idea.

Was it the complete transmission flush ?