Anybody use trans cool, or is it reccomended to use?

I have a 1990 F250 diesel, E40d tranny that seems to be running a little warmer than it should, but not overheating. Thinking about using some trans cool additive.

 

I use the OE transmission cooler in my Bullnose truck.

 

Sounds like a snake oil type product to me. Adding an aux transmission cooler is cheap and effective, but without a trans temp gauge it's kind of shooting in the dark. If your fluid is very old and dirty it may be time to change it. A couple hundred in ATF is a lot cheaper than a rebuild.

 

Never heard of it. Just googled it. Sounds like snake oil for sure. Don't put that in your E4OD. Stick with Mercon 5. If you want to lower trans temps, then install an aux cooler (inline, after the radiator) and actually cool it. Ideal trans temp is 170-180F @ the test port. Anywhere from 170-210F is fantastic (you can run warmer safely too, but you'll cut into the trans fluid change interval quick, warmer than this). Too cool isn't any good either. Just like an engine, there's an ideal operating temp. It's a hydraulic device. It wants warm fluid. A lot of people think if a little is good, then more must be better, so they swap in giant 6.0l diesel truck coolers and don't ever let their trans temps reach 150F haha. It's funny, cus the same people wouldn't run without a thermostat in their engines, I'm sure.

 

good to know thanks! Mine seems to hang around 220F empty at 60, obviously will get a little higher with a load.
I bought a cooler that was supposed to be for a 6.0 but its dimesnsions were exactly the same as what’s in my truck, so I just left it alone. New fluid and filter also a few months ago. The only other thing I can think of is the cooler needing flushed??

 

Is the ATF also routed through the radiator cooler?

 

If rad is bypassed, most aux coolers dont have enough capacity to cool when vehicle is stopped and your trans can overheat when backing up under load or in stop n go traffic. Those that place it under the bumper and not in front of the fan air flow can experience trans failure sooner.