The 68RFE transmission is 100% junk. I have had nothing but issues with them over the years...but I keep buying those damn Rams/Cummins. Majority of the transmission issues come from the celinoid pack and/or valve body.I can vouch for the horrible mileage of my tundra, but I also never had a problem with 6.7 Cummins in 120k, the transmission is a different story….