2017 Tahoe 'Newly' replaced transmission temps

[dejackson1064]

I recently purchased a 2017 Tahoe premier. The unit has 5.3 with a 6l80 transmission which failed within 300 miles of me purchasing the vehicle. The dealership supposedly replaced the transmission I am unsure if it was replaced with new or rebuilt however the new transmission has also failed as of yesterday it also has less than 300 miles behind it. However this time I don't believe the transmission completely shelled out the temperatures became so high that the vehicle went into limp mode and we allowed them to cool down the temperatures got as high as I believe 260 plus degrees we are going to be returning it to the dealership what are your suggestions to what needs to be done. Thank you for all your support

 

[hilson]

What did you end up doing? If a replacement transmission is already overheating and going into limp mode within a few hundred miles, I'd be pushing the dealership pretty hard for a full diagnosis instead of just swapping parts again. I'd want them to check the cooler, lines, thermostat, and anything else that could be causing the temps to spike. I was reading some discussions from Monster Transmission a while back, and excessive heat seems to be one of the quickest ways to kill a transmission, so I'd definitely want the root cause identified before putting more miles on it.

 

[jaxscuby]

transmission main cause of overheating is the lack of fluid. think of all those plates & clutches and no fluid. time bomb waiting to go off.
did you check the dip stick for fluid level?

outside chance..the thermostat stuck and fluid not getting to the cooler.
did you check the dip stick for fluid leve?