Dual Transmission Coolers Install - Give Your Gearbox Goosebumps!

Transmission failure is the kind of catastrophe we loathe more than any other. After all, almost any other kind of break can be bandaged enough to get back to the road from the trail, so you can call for a tow. Even many internal engine failures will allow for that sort of thing.

This isn't the case, however, when a transmission bites the dust (especially an automatic one). There are about a million parts sealed within a tranny housing; there's no sense in trying to crack it there while you're still in the dirt, and you can bet the repair is going to be expensive. For that reason, we find transmission coolers to be necessary additions to our trucks, and when the situation calls for it, we'll utilize two of 'em.

Point in case: our project Bronco had been fitted with a Derale "Atomic-Cool" transmission cooler a few years ago, and it did a great job of keeping the vehicle's transmission temp from getting too high. There's a direct link between a transmission's temperature and its lifespan: a transmission that gets too hot will absolutely fail more quickly than one that stays within a normal operating temp.

At the time, the Bronco was running 33-inch tires and spent lots of time on suburban streets, with the occasional dose of dirt-road driving. Fast forward to present day: our Bronco is outfitted with 37-inch tires and a variety of engine performance mods, and sand dune adventures are a regular occurrence. These all put additional strain on the vehicle's E40D transmission, and although the single Derale unit has done its job admirably, it was time for some reinforcement.

Because the Atomic-Cool unit had done so well, another one was ordered up, and the plan was to run both concurrently. The crew at Peformance Transmission in Lawndale, California, were ready to take on the install. This is a relatively simple process; a second transmission cooler can be piggybacked on a primary unit. A short section of hose was run from the output of the primary cooler to the input of the secondary cooler, and then the output of the secondary cooler was routed back to the transmission itself. These Derale coolers utilize electric fans as well, so a quick wire to a fused switch finishes the job.

The results of this particular exercise dropped the vehicle's transmission temp by about an additional 10 degrees, which is no small feat. With the transmission happily operating at cooler temperatures, we're confident that catastrophic failure is unlikely. An occasional fluid check should be the only maintenance needed until the next scheduled transmission service.