Automatic transmission cooler

Highbeam · Sep 7, 2005

Put it back together the way it came apart. The cooler/heater in the radiator is a very simple tube with fins and is less likely to trap debris than the aux cooler. Get the biggest, new, stacked plate, cooler that will fit and get it installed WITHOUT using those push through the radiator type pins.

The thing about that radiator cooler/heater is that in really cold conditions it actually can add heat to the atf to bring it up to operating temp. Then realize that the radiator atf cooler sits in the cold tank of the radiator after the antifreeze has been as cooled as the radiator can get it. The coolant temperature in the cylinder head will always be higher than in the cold tank of the radiator.

johnday · Sep 7, 2005

Okay, how about the trans temp gauge. /forums/images/graemlins/confused.gif Does it go on the trans inlet, or outlet, and why? Anybody know? I'm really not sure. I went by the directions for mine, and they said to use the inlet side. /forums/images/graemlins/smirk.gif /forums/images/graemlins/grin.gif
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_RaT_ · Sep 7, 2005

After talking to several transmission shops, the comment was that after the Ford C-6 automatic transmission, it is almost impossible to have the transmission oil to cold on a FORD. All have said that the Ford C-6 was the last of a bullet proof tranny. I tend to believe it because after 500,000 on my last truck with a C-6 with ZERO issues on the tranny, it was the best transmission I have ever had manual or automatic. I now have the largest cooler made for a automatic, no radiator cooling/heating since my radiator seems to have some flow restriction. If it lasts for another 6 months, thats good enough because my need for a full size truck is all but gone. I want a compact like a Toyota.

PS the cooler has those push pins like was mentioned that are not as desireable. My comment is WHY? It works so very well. My oil is so much cooler. It was simple. It works well. I'm done! Thats the best part... RaT........... /forums/images/graemlins/grin.gif

BobRip · Sep 7, 2005

I found the 175 degree number in an advertisement in a transmission shop, so you can take it with a grain of salt. They showed a typical life of 20 hours for a transmission at 175 degrees. Probably an exageration, but for the low cost of a cooler it seems like cheap insurance.

My theory is that on a new radiator there is a cool end of the radiator that cools the transmission. As a radiator ages it looses cooling capacity and the cool end runs warmer and warmer. Past a certain point the radiator may remove very little or even add heat to the transmission. On a hot day when your thermostat is fully open and the engine temperature rises the transmission gets less cooling or none at all. That is when the cooler is really needed. Of course if your radiator is old, your transmission has some age on it too. So there is a more rapid wear and you get an early failure.

Bob Rip

HGM · Sep 7, 2005

True, I would be apt to think they mean on the cool side of the cooler though. But, good point about age.

Highbeam · Sep 8, 2005

YOu don't want to use the push pins through the radiator because they rub holes in the radiator tubes. It is hokey at best and there is a reason that no manufacturer would butcher the job like that. They all use brackets and so should you.

My trans temp gauge has its sender in the port on the side of the transmission. This port reads the atf temp before the torque converter. That way I know the true temp of the fluid throughout the transmission where I really care. The TC adds huge heat and then dumps the atf to the coolers. The atf can handle much higher temps than the tranny so I worry about transmission temp not peak atf temp. Lots of controversy there though since many people want to see the peak atf temperature as if that matters. No one seems to believe that you want to know the temp of the atf after the coolers, who cares? So I would recommend the test port, or the hot line out of the transmission before any coolers as the sender location. I really enjoy my autometer trans temp gauge. Be sure to get the one that starts at 100 and goes to 250 or you will never see it move unless you are working it hard. Most of the time my trans runs at 165 while towing. 200 is my high limit.

johnday · Sep 8, 2005

Highbeam; Is this a Superduty you have? /forums/images/graemlins/grin.gif

Highbeam · Sep 8, 2005

Mine's a GM product, 4 speed auto, but the superduty also has a test port for the sender. In fact, the threads are conveniently 1/8" NPT just like the brass sender. It is as simple as remove the plug and thread the sender in the hole. Mine has never leaked.

johnday · Sep 8, 2005

Thanks, now if I knew just where that plug is, I'd change mine over. That is, if the Ford trans circulates fluid like the GM. Mines the 4R100 in a Superdude Stroker. Anybody out there that can confirm this and tell right where that plug is in a Ford? /forums/images/graemlins/confused.gif /forums/images/graemlins/grin.gif