phil-l

Hello! First time poster...

I am shopping for a 2009 (or later, if affordable) 4WD Suburban to tow a 6500 pound camping trailer.

I've been able to find Suburbans in my area (Baltimore/Washington area) that have the RPO code for the 3.42 axle (GU6), and the trailering package (Z82). As I read the owner's manual, such Suburbans are rated to tow up to 5400 pounds.

However, the full 7900 pound max tow rating is only achieved with the addition of the K5L heavy-duty cooling package (based on page 4-53 of the 2009 owners manual) . I believe this package includes only a transmission fluid cooler and engine oil cooler.

So far, I have been unable to find even one 2009+ Suburban for sale in my area equipped with the K5L package. For some reason, they appear to be difficult to find (plus most dealers seem to be unaware of the specifics of trailer towing options).

Question: How feasible is it to add the K5L heavy-duty cooling options to an otherwise-equipped-for-heavy-duty-towing Suburban? Are there other issues I need to be concerned with?

I have added towing equipment to other vehicles, including a transmission cooler, so I'm familiar with the basics of what needs to happen.

Thanks in advance for info from anyone who has tackled this project, particularly on a 5.3L Suburban with the 6-speed transmission.

intheburbs

I currently tow a 6500-lb travel trailer with my 08 Suburban. I first towed it with my half-ton, but I kept breaking things (primarily the rear axle), so I upgraded to a 2500.

Towing a heavy trailer involves a lot more than just "how much can it pull?" Especially with SUVs, you'll exceed other ratings before you come anywhere near the "max tow rating." The two numbers you need to pay attention to are Gross Vehicle Weight Rating (GVWR) and Rear Axle Weight Rating (RAWR).

GVWR is the total amount of weight the Burb is rated to carry on its four tires. For 1500s in the range you're looking at it's 7400 lbs. Subtract the vehicle's curb weight from 7400, and you're left with ~1500 lbs of payload for people, gear, hitch, and trailer tongue weight. Figuring a 6500-lb trailer has about 900-1000 lbs of tongue weight, and that only leaves you 500 lbs or so for you, your family, and gear.

RAWR is the other concern. The rating for a half-ton Burb is 4200 lbs. Again, even with a weight-distributing hitch, you're going to be right at that maximum, if not over it, with a 6500-lb trailer.

If you look at the 2500 Burbs, you get a payload of ~2100 lbs, a GVWR of 8600 lbs, and a 5500-lb RAWR. But even with those higher numbers, I'm still right at my max ratings with a 6500-lb trailer - note the steer axle and drive axle numbers add up to exactly 8600 lbs. Yet my Suburban is "rated" to pull something like a 9500-lb trailer. A trailer that have would have me over on my GVWR.

Here's a weigh slip from a recent trip:




If you get a 2500, it will have all the extra cooling goodies, with the added benefit of an engine with no AFM. If you don't know what that is, Google "5.3 AFM" for some light reading.

Yes, the mileage is not as good as a half-ton, but you'd be overloading a half-ton Burb with a 6500-lb trailer.

Here's our rig:


Feel free to PM me if you'd like more information, or if you'd like to ask questions. I've been towing this trailer for five years, have logged over 25,000 miles towing it around the country, and have been RVing with a TT for 10 years.

phil-l

intheburbs -

Thanks for your input and sharing your experiences!

Yes, I'm well aware of weight issues when towing, having spent years towing a popup camper with a minivan. My combination is close to the ratings, but has performed very well, even on long (1500-2000 mile) trips.

I have spent some time looking at 2500 Suburbans. One hassle: There are very few available. For example, my area's Craigslist currently lists exactly zero 2500 Suburbans less than 10 years old. Budget realities - and the fact that Chevy stopped making the 2500 Suburban after MY 2013 - mean we can't really consider a new vehicle. While I'd personally consider an older Suburban, the Spousal Approval factor comes into play; she wants something newer. We've narrowed to 2009+ models due to the arrival of the 6 speed transmission.

In reality, we're currently looking at hybrid campers with a dry weight of about 4500 and GVWR of 5800 - so we will probably have a little bit more room in the numbers. That said, your math matches pretty closely with what I've done, but I do hope to find a family-friendly hybrid that's well under 6500.

Yes, it's convenient that your weight slip shows your GVW to be exactly on the 8600 pound GVWR for your 2008! Were all typical passengers and their gear in the vehicle for this weighing?

A question: What exactly was failing in your rear axle? I have seen on-line reports of bearing failures.

Further question: The picture of your combination doesn't clearly show the hitch hardware. What WDH/sway hardware do you use?

With the demise of the 2500 Suburban, it seems that the market is abandoning family-friendly vehicles with usable higher-end cargo and tow ratings. Are there other options for those who don't want to squeeze everyone into a pickup (yeah, this is a rhetorical question; the answer is mostly "no")?

Thanks again for your insights!

intheburbs

The weigh slip was from a weigh in the middle of our vacation - we were on a 2.5 week trip out West to the Grand Canyon, Utah, and Colorado. Full tank of gas, trailer fully loaded, wife and three kids in the truck. Our family of 5 weighs ~830 lbs; we have three teenagers.

Yes, the 2500s are rare, but they are fantastic vehicles. Park a 1500 next to a 2500, remove the body, and you have two completely different trucks. The 2500 has a beefier frame and suspension, better axles, hydroboost and bigger brakes, a stronger transmission and a better engine.

When I was ready to buy my 2500, I resolved to be patient, and accepted that it could take several months to find the right truck. I was also willing to drive as far as Texas to get it. I used Autotrader to find mine, and when I ran a search within 250 miles for the price range I was looking for ($20k to $30k), two vehicles came up. I made two trips to Ft. Wayne, 3 hours away, to buy mine. First trip was a test drive and mechanic checkup, second trip was to bring it home. I would've expanded the search to 500 or even 1000 miles if necessary.

My half ton Burb is on its fourth rear end. I've had two major failures in the middle of vacations. First was a pinion bearing failure, forcing an unscheduled 3-day stay in Youngstown, OH. Second failure on vacation was caused by simple overloading/overheating of the rear end, which cooked off all the oil and seized it, forcing a 4-day stay in Mitchell, SD. The third rear end was replaced under warranty, because I was not able to properly break it in. It was immediately thrown into severe service, since I was not willing to drive 500 miles unloaded and lose another day of my vacation.

I use a standard, generic WDH, with 800-lb bars and friction sway brake on my current rig.

The 2500 Burbs starting in 2007 all have the six-speed transmission (6L90 - the heavier-duty transmission). And the LY6 motor in my Burb uses VVT, which gives you both low-end torque and high-revving horsepower. It took me a while to get used to seeing a V8 spinning around 4,000 to 5000 RPM. It loves to rev so much that there is no redline on my tachometer, all the way up to 6,000 RPM.

On this last trip we drove on I70 over Vail Pass and through the Eisenhower Tunnel. One could make a very valid point that this stretch of road is the most abusive on a tow vehicle in the entire nation. Two separate runs to 11,000 feet of altitude with grades up to 7%. The Burb handled it easily.

ETA: A quick search on Autotrader for 2007-2012 2500 Suburbans or 2500 Yukon XLs within 200 miles of Baltimore yields 30 vehicles.