I’m looking to get the notorious 8L90 transmission fluid swapped out with Mobil 1 LV ATF.
I went to the Chev dealer and they said they’d flush it. My mechanic said they’d change the transmission but not the converter, and also said a full flush of the system isn’t recommended as it has close to 100,000 KM on it.
Which option is better, does it matter?
There is no way to drain the fluid from the TC without removing it so a drain and fill leaves fuid in the TC. This is acceptable per the service manual. You could also disconnect the oil cooler line to get more out