2009 Yukon SLT with Factory Tow Package Cooling Upgrade

I have a 2009 Yukon 4wd SLT with Factory Tow Package, and am interested in upgrading cooling system to tow a 7000 travel trailer, which is within the heavy duty tow package for the year.

Is an engine oil cooler and transmission cooler all that is needed?

Looks like your towing capacity is 8200 lbs if you have max trailering? An external oil and trans cooler would be a good start and a great addition to your rig all around.

How far are you planning to go? Any steep climbs? Weight distribution hitch?

If the trailer is 7k alone once loaded you’ll be close to the limit. You’ll get all kinds of good advice from folks here that tow.

drseth said:

I have a 2009 Yukon 4wd SLT with Factory Tow Package, and am interested in upgrading cooling system to tow a 7000 travel trailer, which is within the heavy duty tow package for the year.

Is an engine oil cooler and transmission cooler all that is needed?

Click to expand...

I don't remember, suggest that you check your RPO codes for these:

KC4 - Engine Oi Cooler (I know you don't have it)
KNP - Cooling System, Transmission, Heavy Duty
K5L - Enhanced Cooling Package

K5L includes the first two, an external transmission cooler and an engine oil cooler than goes into the driver's side of the radiator. The radiator has more capacity and the electric fans are 700 watts each versus 500 watts.

You probably already have 3.42 gears (GU6) unless yours is a RWD XFE.

How much you ought to change depends on where you want to pull that trailer.

Not sure your alternator output but upgrading to the highest factory amp one and a set of K5L fans are direct swap.

As James says, we need to know exactly what equipment yours has already. Check the option codes and get back to us.

I tow a 7500 pound camper with our 2012 Yukon XL Denali that came with factory transmission and engine oil coolers, and I have upgraded the fans to the K5L package. I have experimented with all kinds of upgrades including a cold case radiator, a Trucool 40K, and ended up right back where I started with a new factory radiator because the cold case lasted only 3 years. I took out the Trucool because it blocked too much airflow and caused engine cooling problems, so I now have a Derale 13960 fan forced transmission cooler mounted below the front bumper and behind the lower grille. It works fine but frankly the factory cooler would’ve worked just as well if I’d left it alone.

Upgrade the radiator to either a new high quality or an all aluminum aftermarket
like a mishimoto or cold case type radiator. You'll want to make sure
your trans is in Excellent condition. For ease of install, an aftermarket pan
such as the b&M or tci will help with cooling and add a couple more quarts of fluid.
Make sure all your systems are in excellent shape.. you are still 12+ years old
so that alone (w/o towing) deserves some special attention.. Belts, hoses, all fluids,
all filter, differentials, transfer case.
Towing (at max) requires every system to be in "like new" condition

@drseth
Our 07 6.2 Denali has the KNP factory setup, and I can assure you its not adequate for your towing needs.
Do what @Geotrash and @Foggy say.