C4 Temps

I know this has been discussed here in the past ,but I am going to ask anyway. My C4 in the Bronco is just hooked up to an external cooler in front of the radiator. The radiator that the PO had installed was new and so far I have no problems with the engine temps. The radiator has no built in trans cooler in it. For a set up such as this is there a certain size trans cooler I should be running ? I don't want the tranny to run too hot but at the same I was always told you can go overboard cooling one down.

Do you have a temp gauge installed for the transmission?

Well the best temp to run is just under 200 degrees. Temps above 250 start breaking down the fluid quickly and transmission life is greatly reduced. usually you'll want one of the bigger coolers that you can get something thats recommended for the higher GVW's like 15000-24000 gvw. If you drive a lot in colder climates then you might want to go to the lower side of the range warmer driving the higher side. A temp guage would be a good thing to get a idea of your current running temp. As you may not even need another cooler. If its running to cool you could move locations install a small fan on it with a temp switch so it only comes on when the fluid is up to temp.

My preferred method is running the fluid through the aux trans cooller first then back into the radiator internal cooler. This reduces the load on the radiator, but helps warm up the trans if you live in a cold climate.
Tom

His radiator has no tranny cooler built in.

You can get a thermostat for the transmission cooler. This will allow fluid to bypass the cooler until operating temperature is attained.

Thanks guys, it sounds like that the first and best thing to do is to get a temp gauge on the transmission and then take it from there.

I don't recommend a tranny temp gauge. From my personal experience it will drive you nuts looking at it all the time.

I have the following setup on the pressure side of my tranny; an external tranny filter with temperature sending unit, one large Dealre tranny cooler with fan on the wheel well, a second plate cooler in front of my radiator, and steel hard lines on the return side path. The steel hard lines also help cool the tranny fluid on the way back to the trans.

When the C4 is under load it creates a lot of heat depending upon your gearing, torque converter, how the tranny is built and outside ambient air temperature.

Current ambient temps in the Phx area are in the 108 F to 114 F during the day. Everything runs hotter this time of year.

Basically, sometimes not knowning is a blessing, as you don't worry about the small stuff like trans temps.

Just my two cents.