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Legal to tow

bluejaka

New Member
Joined
Jan 6, 2010
Messages
6
I have a 2009 Avalanche LS 5.3 L Flex Fuel truck with 3.42 gears.  I have the towing package just not the HD cooling package.    The manual lists a max trailer weight of 5,500 lbs. 

My question is if the only difference between towing 5,500 lbs and 8,100 lbs is the cooling unit am I legal (and safe) to tow more than 5,500 lbs if I have installed a transmission cooler or is there more of a difference in truck set up than I am realizing?

In addition to the transmission cooler I have also installed trailer brake control and Timbren suspension enhancers and a weight distribution hitch.

I am towing a 3 horse aluminum trailer (2,700 lbs), 2 horses (2,600 lbs), gear (400 lbs) and 4 people (600 lbs) for a total of 6,300 lbs.

The Avalanche seems to tow fine achieving 8-10 mpg depending on the wind direction but my trips to date have all been approx 1.5 hrs or less from home.

Appreciate any opinions on this. The last thing I want is to be uninsured or to fry my truck. 

Thanks!
 
The problem is the 3.42 gears. The higher tow rating is due to the higher gear ratios like 3.73 or 4.10. You need the additional torque multiplication for towing heavy loads.

The tow package was standard on '02's; I have the 4.10 gears and my tow rating is 8100 lbs; I believe tow rating for 3.73's is 7300 lbs.
 
So that means I am towing illegally and doing harm to the truck.  ouble whammy! 

Ughhhh, was hoping to put off upgrading the truck for another year.
 
Nothing illegal about it...it is just harder on the engine and drive line.  You Will have an easier time towing with either 3.73 or 4.10 rear gears...that's all.  The engine will rev higher, putting it into a better powerband for the weight it is pulling.
 
Don't the 2009s have the six speed transmission making the 3.42 ratio equal to a 4.10 with a 4 speed?
 
It says that the truck is able tow maximum with 4wd is 7900 pounds.. I don't see how your illegally towing. There is no way the avalanche can only tow 5500 pounds..
 
OK, this table is from the manual. Sorry it didn't copy better. By towing more that 5,500 lbs I am exceeding the GCWR. 

Vehicle/ Axle Ratio /Maximum Trailer Weight /GCWR *
1500 Series 2WD
5.3L V8 Flex Fuel 3.08 5,100 lbs (2 313 kg) 11,000 lbs (4 990 kg)
5.3L V8 Flex Fuel 3.42 5,600 lbs (2 540 kg) 11,500 lbs (5 216 kg)
5.3L V8 Flex Fuel, K5L HD
Cooling Pkg 3.42 8,100 lbs (3 674 kg) 14,000 lbs (6 350 kg)
5.3L V8 3.08 5,000 lbs (2 268 kg) 11,000 lbs (4 990 kg)
5.3L V8 3.42 5,500 lbs (2 495 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling Pkg 3.42 8,000 lbs (3 629 kg) 14,000 lbs (6 350 kg)
6.0L V8 3.42 8,100 lbs (3 674 kg) 14,000 lbs (6 350 kg)
1500 Series 4WD
5.3L LC9 V8 3.42 5,500 lbs (2 495 kg) 11,500 lbs (5 216 kg)
5.3L LMG V8 3.42 5,400 lbs (2 449 kg) 11,500 lbs (5 216 kg)
5.3L LC9 V8 K5L HD Cooling Pkg 3.42 7,900 lbs (3 583 kg) 14,000 lbs (6 350 kg)
5.3L LMG V8 K5L HD Cooling Pkg 3.42 7,800 lbs (3 538 kg) 14,000 lbs (6 350 kg)
6.0L V8 3.42 7,700 lbs (3 493g) 14,000 lbs (6 350 kg)
*The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment and conversions. The GCWR for the vehicle should not be
exceeded
 
Legal or not, it's unsafe. Better put those horses on a diet >:D (At one time I had a Saddlebred and a Standardbred which each one weighed in as just over 1000# each)
 
If the people and gear are not in the trailer then the trailer weight is 5,300. But the GCW may be over 12,100 if the curb weight is around 5,800. As you said, over the GCWR. Need a scale to know for sure. You *may* be able to do it safely with the aftermarket equipment (less than 14000) but check with your insurance company on the liability aspect, not all policies are the same.

If this is a regular thing for you then I'd say you need a different truck or at least get the passengers out. I think a rule of thumb is don't tow more than about 75% of the rated maximum. Both for safety and longevity. Not good to be running at or near the limits.

 
I gotta weigh in here.

You are fine. Add a transmission cooler and call it a day. The 6 speed trucks are far better off than the 4's. My is a dog because of the 4 speed.

This is close to the limit, but if you are satisfied with the performance I wouldn't worry. I was not satisfied so I added the blower and brakes. It was not necessary but I am towing in harsh circumstances.

Weigh the truck to be sure. So long as it is under 14,000 you are legal. No highway check is going to start searching for your transmission cooler.
 
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