Installing Strictly Diesel’s 6.7L Ford Transmission Cooler
In 2011, Ford released their all-new, in-house developed and built 6.7L Power Stroke engine platform paired with the 6R140 transmission. To say it’s been a homerun, when compared the earlier 6.4L and 6.0L Power Strokes would be an understatement, but that doesn’t mean that Ford got it completely perfect. While the durability and longevity of the 6.7L and that 6-speed transmission has been much improved over its predecessor’s, there are still a few things that the aftermarket has developed that can be a worthwhile investment.
Case in point, the cooling systems under the hood of that 2011-2019 Ford truck. Ford got away from running the standard air-to-air intercooler for the turbocharger system and developed a liquid-to-air cooler as it offered more consistent charge temperatures. They also converted their transmission cooler from the usual big liquid-to-air mounted behind the bumper, to a much smaller liquid-to-liquid cooler that resembled and engine oil cooler. While we can’t say for sure Ford’s reasoning for this, anyone that owns the 6.7L Power Stroke and uses it for heavy towing, will confirm the staggering transmission temperatures they’ll see under load. In the summer months, while towing heavy in a 2011+ Power Stroke, it’s not uncommon to see 240-degree fluid temperatures through that transmission. While Ford suggest this is normal, anyone in the industry will attest to fluid breakdown and heat being the #1 killer for transmission longevity.
Looking to overcome issues with hot fluid temperatures and extend transmission fluid life and overall durability, Strictly Diesel, a big name in repair and performance work out of Phoenix, AZ, went to the drawing boards to develop something that could easily install and help bring those temperatures down. With extensive research and abusive testing regiments with their F450, they came up with the perfect air-to-liquid cooler kit for the 2011-2016 and 2017-2019 Ford applications.
In their initial data collection and testing process, towing an 18,000-lb 48’ triple-axle enclosed trailer with living quarters and their 10-second Power Stroke drag truck they recorded average freeway speed temperatures of 240-degrees. Average unloaded temperatures hovered at 210-degrees, which is still abnormally high compared to other diesel pick-up truck and automatic transmission combinations out there. After finding the perfect cooler and engineering some simple bracketry, the addition of this transmission cooler kit made immediate and effective changes in overall fluid temperatures, netting a maximum of 220-degree temperatures towing once installed.
This system retains the factory transmission cooler but adds the large air heat exchanger directly behind the grille where it can get maximum airflow through the core to help reduce fluid temperatures over the capacity of the stock unit. Adding this cooler takes only a couple hours and will increase fluid capacity by 1-1.5 quarts. In our test vehicle, a 2018 F250 running a mild lift and larger tires, it was common to see 230-degree temperatures towing in the summer and on the morning of our install peaked at 210-degrees with just a 14-foot flatbed trailer and side by side in tow. After installation of the Driven Diesel cooler kit, making the same drive back home with the same load, our fluid temperatures peaked at just 172-degrees with outdoor ambient temperatures at 40-degrees. The addition of the cooler will require some minor cutting to the grille support, but nothing that can’t be tackled by the average mechanic. If your 6.7L Power Stroke is used for heavy towing, this modification is one we’d definitely add to the list of must haves.