Is there any way to safely and or effectively increase the towing capacity? I have a 2007 2500HD with the 5.9L diesel. Factory towing. I tow a 9,000lb dry weight bumper pull toy hauler today, with no problems. I'm looking at 38 and 40' 5ers. One that I really like is 14,000 lbs dry weight. Any chance I make this happen with this truck?

Quad Cab; 4x4; Long bed

 

Gearing would be your only way of effectively increasing towing capacity since you have 17" rims and 31.5" tires already.

 

i'd go with a 5th wheel or gooseneck setup
and air bags or add a leaf to your truck
also do a gear upgrade

 

would this be the 456's?
If I change the rear gears do I need to change the front gears?

 

Yes 4.56 would be good and yes (if you still want a 4x4)

 

excellent, thanks for your help.

 

Towing capacity is towing capacity. Nothing you can do will change it. If you're over-weight and wreck it, you're toast.

 

+1 You can do things (like gears) that make it easier on your truck to tow, but you cannot change the rated capacity.

Your rate towing capacity is derived by many things by the manufacturers such as frame rigidity, the entire drivetrain, suspension, brakes, wheels, tires, etc.

 

Towing capacity is towing capacity but it's equipment dependent! A WD hitch INCREASES rated towing capacity as does the wheel size, a QC Hemi 1500 for example is rated to tow 1000# more with 17" tires than 20" tires.

A 4x2 has approx. 400# greater towing capacity than a 4x4.

I dunno the specs on 2500s or diesels, but increasing from 3.55 gears to 3.92 alone in a 1500 Hemi increases towing capacity by about 900 lbs.

To the OP: If you have 3.73 gears then a step up to 4.10s or even 4.56s would increase towing capacity and also make life a lot easier on your transmission.
Your truck will run if you only do the rear gears, but if you EVER switch into 4 wheel drive, you'll have to tell the flatbed driver to go back and get your transfer case and transmission off the side of the road AFTER he loads your truck up!!!

 

I can tell you if you are stopped and wieghed and are heavier than then your rated wieght you will get a ticket. In my case I was under the vehicles gross wieght but the company decided to save some money and only registered the truck for 6,000# and I was carrying 10,500#. Gross physical limit was 11,000# for the truck. I was allowed to drive off with a $1600 ticket. I believe I would have had to unload the truck if it had actually been over the vehicle's rated wieght, but not sure.