Derale 13740 Hyper Dual-Cool Remote Cooler

I have a GMC Sierra and I decided to add an auxilliary transmission cooler to it. I wound up first purchasing the Derale 15840 that was made for a vehicle with 1/2 inch transmission hoses. It looks just like this one, I found out however that there is a different model number for different vehicle hose sizes. Since GM uses 3/8 in hoses this is the one I wound up installing. To me it was kind of expensive by the time I got everything that I needed to install it but it's a lot cheaper than a new or rebuilt transmission. I read that the thermostats leak sometimes and so I used anaerobic sealant as well as O rings in the connections to it and it did not leak for me. To connect the coolers fans to a switched power source on the vehicle I purchased the GM connector part number 20791502 for 2007-2013 GMC/ Chevy pickups shown in the picture with the purple red and black wires. It plugs right into the unused port number 14 in the box next to the brake pedal. I connected the relays wires to this connector and then to the Derale. The GM connector on Ebay came pre-wired while the one on Amazon does not. Amazon had everything else that I needed to install this including the Derale itself, the inline fuse, the anaerobic sealant, o rings, derale relay, derale inline thermostat , derale transmission line 3/8 hose, derale 3/8 inch mounting kit which includes an inline thermostat, and 10 feet of hose, "but I needed more to install it under the pickup bed" I purchased a second, backup thermostat in case the first one leaked or broke, "which the first worked fine" hmm, well that's all that I can think of right now. The only good spot that I could find for this was under the bed of the truck close to the spare tire. Its working great so far and it has significantly reduced the transmissions temperatures from at times over 210 to about 190 maximum. It was definitely worth the work of installing this. I'll update if anything changes, so far so good its working great. Oh yeah I did have to contact derale at one point about putting the thermostat together and I was surprised that their customer service is actually very willing to help. UPDATE 05/26/20. Well after 16 months of being on the pickup and after even unintentionally driving my GMC through flood waters submerging the Derale its still working great. The last two pictures are the newest ones, and the derale usually keeps the transmission at about 172

This is the second Derale cooler I bought. I have a 37 foot gas tag axle rv with a 454 tbi engine and 4l80e. I have two of the largest B&M cooler with fans, a B&M trans pan which hold 3 addtional quarts, a derale dual cooler, and the cooler that runs at the bottom portion of the ac coil and then to the radiator. Although this kept me between 160 and 180 in the 100-110 F while traveling to and from Vegas in the mid day heats, my trans did not go over 180 on the hills, and on flaf land it stayed at 160. I have room for another derale dual cooler so this will be the last cooler that I will install. I know it seems like I am going over board, but I want to be sure that my transmission gets proper cooling for the out West heat. And, if the pandemic subsides, I am making a trip to Atlanta.The cooler is very compact and it will do the job when called for.

Fits perfect under my saddlebag of my Harley.

Works very well

The Derale 13740 Hyper Dual-Cool Remote Cooler works great. I have been fighting overheating issues with my TCI Super Street Fighter C4 transmission along with a TCI 3000 stall converter. Before I installed the Derale 13740 Hyper Dual-Cool, my transmission temperatures were exceeding 210 degrees F, which is way to hot. After I installed the Derale 13740, the transmission temperatures are below 170 degrees F. Great product, thanks Derale.

So gar so good. I'm sure a larger cooler would be more beneficial, but severally limited to mounting options.

I bypass the radiator and used this cooler by itself. I haven't gotten over 160 degrees and I'm running a 3200 stall torque converter on a tuned cammed 5.3 Silverado with 456. Highly recommend this to anyone with a heating problem or just a sporty engine

Great thanks