Recommended Supplementary Transmission Cooler for 2009 GMC Yukon XL 32-Foot Travel Trailer

Question:

I have a 2009 GMC Yukon XL Denali that I use to tow a 32ft. Travel Trailer Keystone 2920BH that is about 6500 pounds. Im planning a big trip out west this summer and Im a little concerned about keeping the transmission cool on some of the long grades out west. The Yukon has the factory tow package which includes an external transmission cooler. I saw that you have remote coolers with fans. Do you think adding one to my existing setup would be worth while? If so, what would you recommend? Thanks.

asked by: Richard W

Expert Reply:

Transmission fluid cannot be over-cooled and you are making a good investment in the long-term care for your 2009 GMC Yukon XL Denali by adding a supplementary transmission cooler for your summer towing to further cool your transmission over and above the cooling provided by the external cooler you already have.

When it comes to transmission coolers, I recommend choosing the largest transmission cooler that will fit into the available space. The ideal place to install a transmission cooler is directly behind the grill, in front of the radiator and A/C condenser. I recommend measuring the available space so you know what size cooler to look at.

For your 2009 GMC Yukon XL SLT with the 6.2 liter engine, I recommend using the Derale Transmission Cooler # D13504. This is a class IV cooler rated for up to 12,000 lbs gross trailer weight. Combined with your factory cooler, this Derale cooler will perform well when pulling your trailer.

These coolers include a universal adapter fitting, but if you would like a vehicle specific fitting you can use either the Derale Snap-In Adapter Fitting for GM, # D13035, if you have a snap in tube fitting or the 5/8 Inch Inverted Flare Fitting, # D13018, if you have inverted flare fittings. You could also use compression fittings if it is easier for you to just cut the transmission line.

I would recommend measuring the diameter of your transmission line going to the radiator and match that up with the proper compression fittings. The most common size is 3/8 inches, but it would be safe to measure first. I have attached links to the compression fittings that we carry, parts # D13031, D13032, D13033. You will want to install the add-on cooler AFTER the existing one, meaning downstream of it.

I have attached two help articles on transmission coolers for you to look over, as well as an installation video of a transmission cooler on a GMC Yukon XL. The vehicle in the video is slightly different from yours, but the installation process will be the same and it should give you an idea of what to expect.

If you are not able to install a cooler in a good location for air flow then a remote powered cooler becomes a good option, but as long as you can fit one in front of your AC condenser you should be fine with this non-powered type.