I finally had to replace the radiator on my 66 f100, well it was after all 40 years old , anyways I had converted to a C6 behind the 352 a while back and have
been using a external trany oil cooler the new radiator i bought has the cooling
section for auto trany ( the other one was a manual ). the question is should I
just continue to use the external cooler like I have been or should I add the extra cooling from the radiator to the system, that is from the trany to the radiator then to the external cooler then back to the trany? which will cool better ? I dont run the truck in th winter, she goes into storage when the snow flys.

Thanks - Jav

 

180 degrees is ideal.

Do whatever it takes to obtain an operating temp of 180. Much more than that and much less than that will decrease the life of the transmission.

 

i would just leave the t cooler setup as you have it.

 

Personally, since you have the extra cooling capabilities, put them to use. I was going to do the external cooler when I put my truck together, then figured I would just spend the $200 on a new radiator with the cooler built in. I purchased some lines from NAPA, put in a couple of bends and plumbed it all up for under $20.

--Mike

 

Not a good idea. What you are saying is the cooler the better. Does not work that way. Do what it takes to achieve 180 degrees. Just because extra cooling capacity is available does not mean that it is wise to use if it puts the tranny operating temp below 180.

 

So then are you saying that if I'm stuck in traffic on any given day and there is no air passing through my 1.5 square foot auxillary trans cooler, it's still going to be closer to the 180 degree mark than if it's running through my nice big radiator, which is cooling to 180 degrees? Heat is the number one killer of an auto trans and personally, if I can prolong it's life, I'll give it my best shot.

--Mike

 

On a warm day, your radiator isn't cooling at 180 degrees when sitting in traffic.

Besides, a 180 thermostat opens after the temp reaches 180 degrees, so the engine is prolly running closer to 190-200.

180 t/stats were factory installed on all Ford V8 and 240/300 engines from 1965 thru 1979.

A external trans cooler is a far better alternative than the puny cooler in the radiator. When vehicles age, those internal coolers are prone to leak~meaning ATF in the engine~not good. Then there is the chance that the coolers will rust out...now you have water in the ATF...that's real bad. The internal coolers are also subject to whatever the engine water temperature is...have a coolant leak, or blockage~that hot or no water will cause the fluid to overheat. External Coolers...The ONLY way to go.



eco: try sitting in our 405 freeway traffic, or any heavy traffic situation, barely crawling along at 10 MPH. Add the factors that most cars today have cat converters. Where are those hot gasses from those cars exhaust pipes heading? Right to your radiator.


An AOD is subject to failure due to overheating, and NEVER should be driven in heavy traffic in O/D. The constant searching between gears fried those AOD's left and right. Ford had more warranty repair cost $$$$ in the first three years of AODs, than all the previous trans repair costs combined. 1000's of external trans coolers were installed by Ford Dealers nationwide to try and solve the problem. The largest limo company in the world (Dav-El) converted ALL their Town Cars in the 1980's over to C-6's. Figuring out an installation kit from the Ford parts bins was a PITA. Ford went from one of the finest A/T's = C6 to one of the worst = AOD. An AOD needs an external trans cooler to survive...ask any veteran Ford tranny man about an AOD... <<< This is what you'll get.

 

Hmmm, does your nice big raidiator have any kind of fan that sucks air in through it? Not much heat is building up in the trans when you are stuck in traffic anyways, so that condition should be the least of your worries. Heat is the number one killer, but overcooling is just as harmfull as not enough cooling capacity. Like I said, 180 is the ideal operating temperature. Cooling in the raidiator with coolant in the 180 range then again in an external cooler could do more harm than good unless you are building up some serious heat (like from heavy towing). If not, then just the external cooler would work best. Thats what I have and unless my temp sensor is misleading me, my beefed up AOD operates at 180-190...but I do no towing. I only haul light loads in the 100-200 pound range + the weight of myself (190) and the van itself.

 

I see what you are saying. I know better than to be in OD unless I am in wide open freeway driving conditions with a light load or no load. When in drive and in heavy traffic I don't see anything higher than 195. But, I have a "heavy duty" AOD and torque converter. I am not sure about all the differences between my set up and stock, but it has heavy duty bands, a shift kit (shifts hard, which means less heat), a heavy duty clutch pack and the torque converter has the fins situated in such a way that the TC can flow more fluid without overheating + other things.

By the way...why did Ford stop using the 180 degree t-stat??

 

The AOD may not have been the greatest trans out of the box, but many tranny gurus have come up with ways to make them more reliable and perform better. An external cooler is def. a step in the right direction. Mine is rated for vehicles with a GVW of 20,000 lbs I think and it keeps me right at 180 in most conditions and never at or above 200.

 

My understanding is that the tranny fluid "cooler" in the radiator is also a tranny fluid "heater" during cold weather operation.

Auxillary coolers, like identification marker lights on a truck cab, really aren't something necessary on non-towing vehicles. As soon as you add the heat generated by torque convertor slippage under heavy load, like the C6 that has no lockup capability ... pulling a long grade in high temperatures, you better have something there besides the radiator heater/cooler.

We did a couple trips in triple digit temps pulling a fifth wheel up some long grades and I was running 210-220 fluid temps with the radiator cooler/heater and a 24 plate aux. tranny cooler that was part of the trailer towing package in '84. The slippage would register on the tach as more RPM's than normal at a given speed. I recently added another 27 plate cooler in series and am thinking about adding an air flow regulator (something like a heater door) so I can adjust cooling capacity of the added cooler. Open=more cooling for towing in hot weather, closed=less cooling for solo operation.

I've only put on ~15 miles running solo since I added the second cooler but I thought 130-135* might be a little cool.

I had heard that the 180* thermostat was replaced by the 195* because an engine tends to burn cleaner at higher temps.

In traffic there is always that shift indicator position labeled "N". You can shortly ruin any automatic transmission by locking up the drive wheels, reving up the engine and letting that torque convertor build pressure/heat.

You also build heat by long term holding the brake ... even at an idle. Then when you thow in an AC condensor pumping heat into the limited airflow across a warm radiator that's heating the transmission fluid ... rather than cooling it, you get a hot tranny. The "N" position lets the engine rev more freely, which facilitates air flow and you may have to give up the AC if the coolant temp gauge is climbing.