Green02z71

Thanks for the information. I worry about the ATF being too cold in the winter, but I'll probably throw the bypass in anyway. We'll see.

Excellent information and it all makes sense. Thank you. I'm only looking for a more "reasonable" tranny temperature, not 140F all the time. What you say makes me wonder how the NHT max trailering people manage such low tranny Temps.? Thanks again.

Hey All, I've been combing through the forums looking for all the information that I can find on the LZ0 and it's transmission and the relatively high transmission temperatures. I just bought a 24 LTZ LZ0 and also think that the temperature is too high when just driving around. That said, it seems like GM has made an effort to make sure there is an elevated tranny temperature by (from what I've read) adding a transmission fluid heat exchanger that uses engine coolant to either warm up or cool down the tranny temp. depending on which is hotter. Now, if that's the case, deleting the transmission thermal bypass valve and adding a bigger cooler will certainly help to bring the temp. down but won't we still be fighting the engine coolant temperature that runs at 200ish F? Would it not be wise to lower the coolant temperature by replacing the thermostat with a lower temp. model? Then the ATF would only be exchanging heat with a 180ish F coolant temp. I wonder if anyone has replaced the factory thermostat with a 180, and if so, did the tranny temps. also drop as a result? Then of course there's the how cool is too cool question which goes back to the seemingly deliberate high temperature that GM has these trannys running at. Are they supposed to run above xxxF minimum temperature? UGH! Any help or answers would be appreciated. BTW, I have the PPE bypass block and tranny cooler ready to go in, just haven't pulled the trigger yet.