BuckyB Posted January 16, 2021 Share Posted January 16, 2021 I recently purchased (haven't taken possession, it’s being shipped from NJ) a 2018 TC w/2.5L. I’ve only owned one automatic in my life (1991 suburban with a 700R4 trans), after it went out I rebuilt it and added a shift kit and a transmission cooler. Clearly adding a shift kit isn’t an option but a trans cooler is vital due to adding fluid capacity and a cooler transmission is a happier transmission. Has anyone here added a transmission cooler and if so what unit was used? Quote Link to comment Share on other sites More sharing options...
Fifty150 Posted January 16, 2021 Share Posted January 16, 2021 How mechanical are you? It can be done. Remove the front bumper, grille, and fascia. You will see the actual steel bumper bar. You will probably mount your aftermarket cooler there. It will be right in the front where you get better airflow. I would tap into the return line, where fluid returns to the sump. My reasoning is that I want the fluid to pass through the cooler bypass valve, flow past the OEM heat exchanger, then to an auxiliary cooler. That should be under the air box and intake hose, near the vent port on top of the transmission. Then it's a matter of cutting and flaring the OEM line, and connecting it to the auxiliary cooler. Based on previous experience installing auxiliary coolers, I prefer to install coolers with electric fans. A little bit more work. But it makes a huge difference. Quote Link to comment Share on other sites More sharing options...
G B L Posted January 17, 2021 Share Posted January 17, 2021 I have done a lot of towing with mine. I have had the scan tool monitoring the fluid temp on lots of runs both with and with out the trailer. The fluid temp was regulated by the thermostat and not the size of the cooler. The biggest issue for transmission heat is how much time this transmission spends with the converter in lock up mode. Quote Link to comment Share on other sites More sharing options...
Double Nickels Posted January 18, 2021 Share Posted January 18, 2021 Modern transmissions are designed to operate with fluid temperature sensor between 200° - 225°. A lot of confusion from old tables showing 185°. Maybe a 40 year old car from the 80's, where you install an inline thermostat, you want to see 185° on the return line. A lot of those charts online show how ATF degrades as temperature exceeds 185°. Probably true with 50 year old Dex/Merc. I believe that modern transmissions and ATF formulas are better than that. Quote Link to comment Share on other sites More sharing options...
G B L Posted January 18, 2021 Share Posted January 18, 2021 (edited) 7 hours ago, Double Nickels said: I believe that modern transmissions and ATF formulas are better than that. They are for sure. My experience with this gearbox F6-35 is that it works the fluid hard. Having done 4 fluid changes on my rig and similar changes on other transmissions. Keeping the fluid clean and fresh is cheap and easy. So if you work the car hard why not. Edited January 18, 2021 by G B L Quote Link to comment Share on other sites More sharing options...
BuckyB Posted January 19, 2021 Author Share Posted January 19, 2021 It wouldn’t be an issue installing an aftermarket cooler, just wanted to ask to get an idea how much room I’m looking at to get something ordered up. I know ATF makes a good HYD oil, any hyd oil over 180 degrees you’ll start seeing seals hardening etc. i do agree with an addition of a fan, then it comes down to the largest cooler i can put in there with an electric fan. Quote Link to comment Share on other sites More sharing options...
Fifty150 Posted January 19, 2021 Share Posted January 19, 2021 It's been in the back of my mind to install a cooler. I've even looked at a few. Here is what I see. The splice should be on part #5, the line which returns fluid to the transmission. On 1/16/2021 at 1:00 PM, Fifty150 said: That should be under the air box and intake hose, near the vent port on top of the transmission. I was wrong about that. It looks like that's actually part #6, the cooling line. It goes to part #2, the bypass valve. If fluid is hot enough, usually 185 or 190, it will go to part #1 the heat exchanger. A combination of regulated flow coolant and air dissipates the heat from the ATF. With FORScan, I've monitored the ATF temp. With my driving style, the OEM system is sufficient and I am not overheating. That may be different for everybody. These are a few of the coolers I have considered. Quote Link to comment Share on other sites More sharing options...
BuckyB Posted January 19, 2021 Author Share Posted January 19, 2021 I do know the cooler has to be after the bypass valve for cold weather startup and driving, unless the coolers max pressure is far beyond what pressure the transmission produces. There again, it’s been a long time since I’ve owned and fiddled with one, and I was always told and I’ve installed. few over the years, when installing an aftermarket cooler you abandon the one in the radiator (clearly this isn’t in the radiator and thanks for the great illustration). Hence the the cooling system regulates the trans temp. NOW, without looking it up I’m certain the OEM thermostat is every bit of 195 to 210 (I’ve seen 220 on some of our fleet vehicles) degrees. And 220 is too hot for any HYD oil. When my new to me van shows up I’ll keep everyone posted on what I find and what direction I went. Quote Link to comment Share on other sites More sharing options...
Fifty150 Posted January 20, 2021 Share Posted January 20, 2021 2 hours ago, BuckyB said: when installing an aftermarket cooler you abandon the one in the radiator I guess I was taught different. I install the auxiliary cooler inline after the OEM cooling system. So if there is a heat exchanger in the radiator, the aftermarket unit provides additional heat dissipation after the fluid has passed the OEM cooler. 3 hours ago, BuckyB said: I’ve installed. few over the years, Installing auxiliary coolers was something that used to be regarded as something that you had to do with off-road vehicles, trucks & vans used for hauling & towing, performance vehicles used for racing, and if the vehicle was in use for hours all day. It used to be believed, and it may have been true, that the OEM system was engineered for short trips, commutes, getting groceries, running errands. Great if you drive for less than 30 minutes to get somewhere, then the car is parked for over an hour to cool off, before you drive another 30 minutes back home. My pickup is a 2007. When it was new, I bought a large, B&M Racing cooler with a fan. A guy I know who owns a shop told me to hold off on installation. He said to drive it and monitor the temps first, and get a good base of data. This was over 10 years ago, actually 14 years ago, and even back then, he said that the modern cars are engineered better. He told me that modern OEM cooling systems evolved to being efficient, and if my ATF temps spiked to 250, there was a problem with the transmission that a cooler won't fix. Or that I was hauling too much weight, towing too much weight, or just driving way too fast. I've never overloaded any of my trucks. What I do notice is that if I'm driving 80 - 90 mph, where I go full open throttle to pass slower cars, the transmission is not in overdrive, downshifts heavy, and transmission temps are higher. Or if I am climbing steep grades at freeway speeds, uphill at 60 - 70, the truck does downshift and the engine revs up. Considering that I can't go uphill all day long, or drive 90 mph all day long, the ATF temperature does lower as I slow down, or stop. So in that sense, the cooling system works. With that in mind, I do live in a city with very steep hills, and a lot of rush hour type, stop and go traffic. So 14 years ago, with the pickup, after driving it around for 1 year stock, I did install the aftermarket cooler. The temperatures still gets up to 220 - 230, and the temps drop back down to 185 - 195. I can't tell if the cooler adds any efficiency towards lowering the temps, as the temps got up to 230 with and without the cooler. I do know that the cooler works. I measure the line temps, and I can see that the line from transmission to radiator is hottest, the line from the radiator is cooler as it goes to the auxiliary cooler, and the transmission line from the auxiliary cooler back to the transmission is the coolest. A thermometer confirms, as does touch of the hand, that the line in side is warm from ATF entering the cooler, and the line out side is cool to the touch. I do know that the fan on the cooler turns on as regulated by a thermostatic switch. But it's impossible for me to guess at how the auxiliary cooler benefitted my truck. No noticeable difference in performance. ATF temperature consistently heats up and cools down depending on driving activity. 2 hours ago, BuckyB said: the cooling system regulates the trans temp The coolant feed to the heat exchanger is controlled by electronic valves. Coolant will only flow as needed. From what I remember, coolant from the overflow tank goes to the heat exchanger, then flows towards the heater core. The heat exchanger has fins for cooling by airflow. I don't know how much cool air you get under the hood, above the transmission case. From my swiss-cheese memory, I have only seen ATF temp from the sensor read up to 220. In theory, 250 is the danger zone where you want to pull over, park, idle the engine, and lift the hood, so that the ATF can cool down. A lot of people, myself included, still aren't comfortable with average ATF temps at 225. I still don't trust that it's fine even at 235. Another thing I don't trust is that when they say the pink color is just a color additive, so when the ATF looks black, it's still perfectly fine. 2 hours ago, BuckyB said: I’m certain the OEM thermostat is every bit of 195 to 210 Only 1 way to know. Test it. I have seen on other forums where people use a point and shoot thermometer to check the aluminum line temperature as the bypass valve closes. Other people have removed the bypass valve, and boiled it to see what temp the water gets to before the valve pops closed. Against conventional wisdom, some people remove the bypass valve entirely, without worry of "overcooling" the transmission. Just a few inches of transmission line will "bridge" the cooling and return lines. Then ATF will always flow through the cooling system. It will take a little longer to "warm up" the ATF. But that does nothing for when the ATF gets really hot. Rare, but it does happen, is the cooler bypass valve being stuck open. BuckyB 1 Quote Link to comment Share on other sites More sharing options...
G B L Posted January 20, 2021 Share Posted January 20, 2021 16 hours ago, Fifty150 said: so when the ATF looks black, it's still perfectly fine The Mercon, Valvoline Maxlife Were Very dark after 25000 miles, The Triax fluid was in much better shape after 25000. Just my experience. Quote Link to comment Share on other sites More sharing options...
Fifty150 Posted January 21, 2021 Share Posted January 21, 2021 11 hours ago, G B L said: much better shape after 25000 Just by the way it looks? Or did you get oil analysis? Quote Link to comment Share on other sites More sharing options...
G B L Posted January 22, 2021 Share Posted January 22, 2021 Oil analysis is out of my league . Just by look smell and passed through a coffee filter leaving no residue. Quote Link to comment Share on other sites More sharing options...
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