BJS
Full Access Member
powerboatr
Honestly from what I have seen with mine and from reading other's responses I would recommend that you put an auxillary trans cooler in front of the radiator. ford put them there on some models and I'm sure that your tow boss has one. Ford really didn't compensate for backing the heavy loads that the trucks are rated to tow. The stock trans cooling system works acceptably as long as you are going forward and with the torque converter locked. When you have to run with it unlocked for whatever reason or are backing up it generates lots of heat. You really need to determine the size of the cooler if any is present in front of the radiator. You can get a larger trans cooler and simply replace it. More than likely the cooler is a tube & fin design which is less efficent when compared to stacked plate design. You will find many people who will tell you that you can't overcool an automatic transmission however they were designed to work in a specific heat range so its' best to run them right around 180 hence why ford put the cooler bypass valves on the 4R100 and I'm sure something similar on the torque shift tranny. This theoretically allows you to put whatever cooling you want in the circuit and the transmission will regulate itself. Quite a few people have put the tru-cool 4590 in addition to the cooler that is built into the radiator and have reported that they are seeing controlable transmission temperatures. The downside is that many of the people in colder climates have reported that with that cooler present they are not seeing any detectable transmission temperature in the winter months in the colder climates and actually some in texas saying winter temperatures barely moved the trans temp guage. Most guys said that except for a slight rise when backing they were running between 80-90° over ambient temperature. The option that I have sitting in the garage waiting to go on the truck is the tru-cool 4739 with the external bypass. The external bypass is an additional thermal bypass so that you will allow the temperatures to reach ideal operating temperatures. The 4590 is a 28k GVW cooler while the 4739 is a 40k gvw cooler. (why are they rated by gvw not BTU?
) It is my opinion that with the additional cooling between the two you need the thermal bypass option especially when running unloaded. You can pick up either model from here. Including shipping that is the cheapest place I've found them except for an occasional auction on ebay for $5 less or so. And as yet another option for you since you're looking specificially to keep the transmission cool you can look at coolers that have a fan attached to them which should give you the additional cooling for the transmission specifically. There are variants available where the fan will turn on when the temperature of the fluid reaches a specific temperature and others where you will need to control the fan manually though as you can see here they are a much more expensive option.
The reason reverse generates more heat is because the internal mechanisms of the transmission require more fluid to move the same distance when compared with the forward gears. When given the same volume but heating up even more fluid in the same amount of time. As well as the fact that you will never lock your torque converter in reverse.
Honestly from what I have seen with mine and from reading other's responses I would recommend that you put an auxillary trans cooler in front of the radiator. ford put them there on some models and I'm sure that your tow boss has one. Ford really didn't compensate for backing the heavy loads that the trucks are rated to tow. The stock trans cooling system works acceptably as long as you are going forward and with the torque converter locked. When you have to run with it unlocked for whatever reason or are backing up it generates lots of heat. You really need to determine the size of the cooler if any is present in front of the radiator. You can get a larger trans cooler and simply replace it. More than likely the cooler is a tube & fin design which is less efficent when compared to stacked plate design. You will find many people who will tell you that you can't overcool an automatic transmission however they were designed to work in a specific heat range so its' best to run them right around 180 hence why ford put the cooler bypass valves on the 4R100 and I'm sure something similar on the torque shift tranny. This theoretically allows you to put whatever cooling you want in the circuit and the transmission will regulate itself. Quite a few people have put the tru-cool 4590 in addition to the cooler that is built into the radiator and have reported that they are seeing controlable transmission temperatures. The downside is that many of the people in colder climates have reported that with that cooler present they are not seeing any detectable transmission temperature in the winter months in the colder climates and actually some in texas saying winter temperatures barely moved the trans temp guage. Most guys said that except for a slight rise when backing they were running between 80-90° over ambient temperature. The option that I have sitting in the garage waiting to go on the truck is the tru-cool 4739 with the external bypass. The external bypass is an additional thermal bypass so that you will allow the temperatures to reach ideal operating temperatures. The 4590 is a 28k GVW cooler while the 4739 is a 40k gvw cooler. (why are they rated by gvw not BTU?
) It is my opinion that with the additional cooling between the two you need the thermal bypass option especially when running unloaded. You can pick up either model from here. Including shipping that is the cheapest place I've found them except for an occasional auction on ebay for $5 less or so. And as yet another option for you since you're looking specificially to keep the transmission cool you can look at coolers that have a fan attached to them which should give you the additional cooling for the transmission specifically. There are variants available where the fan will turn on when the temperature of the fluid reaches a specific temperature and others where you will need to control the fan manually though as you can see here they are a much more expensive option. The reason reverse generates more heat is because the internal mechanisms of the transmission require more fluid to move the same distance when compared with the forward gears. When given the same volume but heating up even more fluid in the same amount of time. As well as the fact that you will never lock your torque converter in reverse.
