I'm still with the 47re and with mine, the first thing to do when you want some engine braking is punch the OD button to off. When descending a long grade I will also pull it down into a lower gear to keep the speed at a safe level, just watch the tach and don't exceed the redline rpm's of the engine. With your foot off the accelerator, the torque converter will be unlocked and will generate some heat but not nearly as much as going up the grade with hammer down enough to disengage the torque converter. I have about 115,000 miles on mine and probably half of it towing a 31' fifth wheel. bg