Transmission Cooler Recommendation for a 2007 Hummer H3

Question:

I am shopping for a transmission cooler for a 2007 Hummer H3 with GM 4L60-E transmission and 3.7L LLR inline 5 engine. I tow a 3200 lb. trailer in the Colorado high country, and after my first trip over Rabbit Ears pass, when my transmission fluid temperature got up to 244 degrees F, I know I need an accessory cooler to prolong transmission life. What would you recommend? I see GM Canyon pulls up Derale D13504 and others. Would that be a good option? Thanks for any help you can provide. Regards,

asked by: Jeff

Expert Reply:

Since the H3 and Canyon/Colorado share the same platform and some of the same engines, it would be safe to use the Canyon as a benchmark for a transmission cooler. I would choose either the # D13504 or part # D13502. If you use the H3 in the winter, the D13504 may require a bit more warm-up time to get the trans fluid warm. Both should help bring your transmission temperatures down.

The measurements for both coolers are listed on their pages. Make sure you have enough room to install them on your H3. I have added a link to a video of the D13502 being installed on a Honda CRV to give you an idea of the process.

expert reply by: Patrick B