Heat can kill stock Duramax transmissions. For drivers who tow, race or simply run their diesel hard, proper cooling of your Duramax engine's transmission fluid is one of the most important things that you can do to increase the life of your transmission. Pacific Performance Engineering's Performance Transmission Cooler is a bolt-on replacement part for your 6.6L that adds 60% more surface area for heat rejection. It lowers fluid temperatures up to an additional 20 to 30 degrees from the LB7 stock unit.
If you’ve added a high-performance transmission kit, the mainline pressure is increased, causing additional heat to be generated. In these cases, we especially recommend the Pacific Performance Engineering Duramax 6.6L LB7 Transmission Cooler. Installation is a snap - it uses the factory oil lines and usually takes about half an hour.