I drive my '53 F100 in parades. I leave the E4OD trans in 2nd gear, and cruise at idle speed. The parade last less than 1/2 hour.

My trans cooler consists of a line from the trans pump through the bottom of my engine radiator, then a multi row cooler under the engine oil pan, before going back to the return connection in the trans.

My radiator is cooled by a fan turned by the motor, but there is no shroud. It also has a 16" electric 'pusher' fan in front of the radiator.

In a parade, the coolant temp can exceed 200F degrees at the temperature sensor in the motor. I suspect that the coolant at the bottom of my radiator is also quite warm.

So, I think that I am heating the trans fluid with my cooling system, rather than cooling it.

I could reduce the temperature that my electric fan will turn on, but then my motor may be operating too cold. I could also install a switch to turn the electric fan on when in a parade or heavy traffic.

Another option would be to bypass the radiator altogether, and put a fan on my external cooler.

Does anyone know of a setup like that?

Do any cars or trucks still use radiator coolers?

 

How hot is the trans getting? Are you trying to fix a problem that doesn't exist?

There has to be a temperature drop across the radiator or the engine temp will just continue to climb. That lower temp is what is around the trans cooler. So if it is only a 15°F degree drop then it can't be heating the trans any higher than 185°F. That's a good temp for the trans to run at.

If you turned the electric fan on at a cooler temp that should not make the engine run colder. The engine has a thermostat to keep it from sending coolant to the radiator when it is cooler than the thermostat temperature.

Anything more than the lightest duty vehicle still has a trans cooler in the radiator. Ford deleted it in 1999 in the Superduty. It went back in production mid year 2000 after replacing many burned up transmissions under warranty.

 

Mark,
I use a Baumann Comtroller. I got a message on the display that read 1.06, I assume that it's a fluid temperature error. I can find no definition for the in the Baumann Manual, but I am waiting for a reply from Baumann about it's definition.

I can monitor Trans Fluid Temperature with the Baumann, but I was not doing that at the time. I'll try that after I hear from Baumann.

 

If it was me, I would bypass the radiator, then move the transmission cooler in front of the radiator or anywhere else you get better airflow. Possibly a pair of small fans (computer?) mounted to keep air flowing.
At low speeds the radiator is pumping more heat into the fluid than the cooler can dispose of.

 

That's what I am thinking. I plan to monitor the trans fluid temperature the next time I take the truck out. I can place a 7" fan on the external cooler, and check the temperature again to see if it helps. I ran the same radiator without an external cooler when I had a C6 trans. No trouble then.

The Baumann tech doesn't know what that code means, so there is no help there.

 

I don't believe that for a moment. I've tested this, in stock trucks, not his truck, but I never found a condition where the radiator heated the trans fluid. That's a myth that just won't die.

 

not to argue. So, If it makes you happy you can read the 'is' to mean 'may be'.

It's a heat exchanger, which consists of a tube passing through hot water. If the coolant is warmer than the ATF, the ATF will be heated
If the coolant is colder than the ATF , the ATF will be cooled.
Heat WILL be passed from the warmer fluid to the cooler fluid.

 

I will monitor the Fluid Temperature to see how warm it gets, but I won't be driving at slow speed like in a parade.

 

That's all true. What I am telling you is that in extensive testing on many types of vehicles, both heavier and lighter than what we are talking about here, I never found a condition where the coolant in the bottom of the radiator was warmer than the ATF coming into the radiator cooler.

 

I monitored the Fluid Temperature while idling. While waiting for the water temp to come up, I realized what the 1.06 that I had read on the Baumann display meant. That is the TPS voltage at idle.

It was a cool day. The outside temperature in the mid-afternoon was in the low 30s. Not much different from when I had the problem.

The reason that I thought that I had a fluid temperature is because I could smell trans fluid.

I let the engine idle for more than 1 hour total. The motor reached about 185 degrees, and the electric fan began to cycle. That is as warm as the engine got.

The trans temperature began to rise slowly, until it reached about 145 degrees. The trans had been in neutral for this period, At that point, I put it into 2nd gear, and held the brake. The fluid temp started to climb faster, and soon reached 205 degrees, then I shut the motor off. The water temperature was still about 185 degrees.

How hot is synthetic fluid allowed to get?

 

Synthetic can go well above 300°F with no damage.

When I was at Ford we supplied 4R100s to an off road race team. They had their trans cooler get packed with sand, enough to fail the fan. The trans temp gauge only read up to 320°F. It was pegged for the last few hundred miles of the race. The trans kept going and they won the race.

The post race teardown showed no major damage. The solder had melted off the solenoids, so we know the trans was above 450°F!!! It was running Mobil 1 Synthetic ATF.

 

Mark,

Thanks, that's good to know. Heat flows downhill, from the warmest to the coolest. The engine makes heat, and it's pumped into the radiator. As the water passes through the core, it's cooled, but with enough flow the water temperature only needs to drop a few degrees from the top to the bottom of the radiator to dissipate the engine heat.

The trans also makes heat, and the fluid is pumped through the cooling tube in the radiator. The fluid temperature will be the sum of the residual engine heat plus the heat generated in the trans. As the engine warms, the trans fluid temp will also rise, until both the engne and trans reach equalibrium. The trans fluid temp will always be higher than the water at the bottom of the radiator, but not necessarily higher than the engine temperature.