yeah i think the 5R110 torqueshift transmissions have a thermostat built in the trans that limits the amount of flow to the trans cooler. I was going to put an extra cooler on the trans, but I am afraid of the thermostat opening and closing all day long with the temp coming up then the cooler cooling it to the point where the thermostat closing the cooler. you know what i mean. but i have plenty of friends that have these transmissions and they never get hot. I am just adding the Mag hytec trans pan which just adds about 8 more quarts of fluid. My friends have actual aftermarket trans temp gauges and they never get over 165 degrees even on a hot day towing a trailer with about 6000 lbs on it.