ATF Fluid Life with in radiator cooler.

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I noticed that on charts for transmission fluid temperature they say that fluid temps over 200F reduces its life expectancy. http://www.tciauto.com/Products/TechInfo/trans_life_expectancy.asp http://www.digi-panel.com/digidevicesweb/trannyoil.htm My radiator gets up 212F. According to these charts, my fluid won't last more than 50,000 miles. Most vehicle today have their ATF cooled by the radiator, and most cars have thermostats over 200F. This does not sound right. The fluid must last longer.
 
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Usually where the trans cooler lines go into the radiator tank on the driver's side it has already been cooled meaning the radiator fluid. I have an infrared gun and when I go across the radiator from where the upper radiator hose comes in to the other side where the trans cooler lines are the temp difference is usually between 60 and 80 degrees cooler. What brand of ATF are you using.
 

Loobed

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 Originally Posted By: c3po
What brand of ATF are you using.
mostly El Cheapo Supertech and some Castrol. I have a drain plug on my 4L60E transmission and usually drain and refill 3 to 4 quarts (from a total of 12qta) a year at the same time I change my engine oil: it gives me a warm fuzzy feeling. What is the temperature of the incoming tranny line to your radiator?
 
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I will have too aim an infrared gun at it when I drive the car again, but here is the problem since my reading will be different. I have a Turbo 350 transmission, that has a Derale Trans Pan with cooling tubes at the bottom, I think they make a pan for your 4L60E. I have no A/C, so I have no A/C Condenser, so I have a lot of air coming into the engine. I am running Amsoil ATF, and awhile back I auto-rxed the transmission which really cleaned things out. What type of GM vehicle do you have.
 
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Radiator coolers for ATF also help by warming up the ATF in cold weather and cold starts. Your engine temp may be 210, but the fluid in the radiator is much less [because of the thermostat]. Don't get me wrong, auto trannys and power steering systems get HOT. The general rule in chemistry is that the speed of a chemical reaction doubles with every 17 deg F rise in temperature. So keeping your tranny fluid cooler is a good idea. Consider an aftermarket one in series with the stock one. Block off the fins of the aftermarket one in very cold weather.
 

Loobed

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I think the tranny fluid gets hot before the engine does. Stalling the converter generates a lot of heat. Mechanical energy is converted to heat energy. I was looking for a good large flat plate after cooler. The thing that doesn't make sense is cooling the fluid after it has already went over the required temp. It's like putting a chastity belt on a woman after she is already pregnant.
 
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 Originally Posted By: Loobed
I think the tranny fluid gets hot before the engine does. Stalling the converter generates a lot of heat. Mechanical energy is converted to heat energy. I was looking for a good large flat plate after cooler. The thing that doesn't make sense is cooling the fluid after it has already went over the required temp. It's like putting a chastity belt on a woman after she is already pregnant.
I have good news for you, B&M makes a stacked plate transmission cooler that has a bypass in it, when the fluid is cold (thick) the trans fluid bypasses the cooler, when the trans fluid heats up (thin) the trans fluid goes through the trans cooler, so there is no need too block off the trans cooler in the winter time. With the stacked plate trans cooler there is much less pressure loss than the tube and fin type cooler, also the tube and fin cooler does not have a bypass and that is why guys that have this type of cooler have it blocked off in the winter time. The stacked plate design also allows faster warm up for the trans fluid. You can pick up one of these coolers from Jegs or Summit Racing.
 

Loobed

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 Originally Posted By: c3po
I have good news for you, B&M makes a stacked plate transmission cooler that has a bypass in it,.... The stacked plate design also allows faster warm up for the trans fluid. You can pick up one of these coolers from Jegs or Summit Racing.
Thanks!!!
 
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 Quote:
The thing that doesn't make sense is cooling the fluid after it has already went over the required temp. It's like putting a chastity belt on a woman after she is already pregnant.
Unlike getting a woman pregnant, ATF aging is somewhat a time weighted average. Look at your chart and factor how long you're at any given fatiguing temp. There's also no other way to handle it. You cool the bulk temp to limit the duration and amplitude of the peak temp. If your wallet is thicker, get a thermostat and run it from the trans to the in-rad cooler while in short circuit/bypass mode (cool/cold). As it warms above threshold it will put the auxiliary cooler in line. It should make for interesting sweeps on a temp gauge. All kinda warm and fuzzy as it self regulates in and out ..up and down (Miyagi say, up down ..breath in ..out)
 
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Here's a flow path I never thought of for thermostats. I have the Perma-cool 4 port and noted that they recommended an alternative routing by plugging the normal cooler return and tee'ing it into the cold return line. It never occurred to me to rig it the other way around to use it as a return temp regulator. This might be useful to someone who has issues with converter lock up when trans temp is too cool.
 
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I have a 2005 Toyota RAV4 that has a differnt type of coolant/radiator cooler. It gets the coolant from the engine just before it goes into the engine from the radiator. That is the factory set up. What I did is placed a small inexpesive cooler in front of the radiator. I am glad I got the smallest one because anything larger wouldn't fit. It is in series with the factory cooler. The aftermarket one gets fed first, then the factory cooler. This has also increased the fluid capacity. Not much, but some. It has been over 4 years with no issues as of yet. I know todays trannys are temperature sensitive so the warming/cooling it gets seems to work well. In the winter, it works the same as it did prior to the install. The fluid needs to hit a set temp to shift into overdrive. I think any additional cooling will help any automatic tranny. But most of all, changing the fluid and not beating on your vehicle is key.
 
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