Overheating transmission

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StephenW

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2015 -Yukon XL Denali with 190k miles. Transmission overheated 2 days ago. Changed out the fluid and filter (overdue). Nothing remarkable on the magnet or in the fluid - just dirty.

Just drove it after the change out and temp was 225-250 and rising in 25 min of driving. Am I just screwed into a transmission replacement?
 

tom3

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Does this year have the thermal control valve on the side of the transmission where the cooling lines connect? That could be stuck or plugged somehow.
 
OP
OP
S

StephenW

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Yeah unfortunately I am not savy on the system. I would love a diagram to see how everything flows and what could be a fail point. Like - is there a TXV or thermostat that could have failed?
 

NickTransmissions

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Cooler Bypass Valve aka Thermal Bypass Valve aka Transmission thermostat.

Check out the Tech Svc Bulletion if you havent see it already. There's an updated CBV from GM but it simply lowers the temp the thermostat begins to open. Id rather delete it all together...
 

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