Probably 60K for me. Unless you are towing heavy, there is no really reason to change it sooner. Transmission fluid basically just circulates in the sealed system. No combustion by products or fuel contamination to worry about. Obviously doing it sooner won;t hurt anything, but it seems like a waste of good fluid to me.
at the rate I appuse the truck in, I change oil every 30,000 to 40,000 but we have nice cool weather aaround here where it stays around 110 to 130 all summer long
Dang Robert, sorry I missed this one. I changed my truck over to AMSOIL at 10k miles. Had the dealer do a fluid exchange. then I changed out the filter and fluid at 77k. Had it sent off and it was still good. I just did another fluid exchange via the transmission return line with 14qts of the AMSOIL ATL but didn't mess with the filter and the truck now has 135k. In general every 50k is a good rule of thumb depending on the vehicle. Now our Acadia I changed it over at 5k and will do it again at 35k. No filter to service, just drain and refill.
