How much over GVWR is too much for hauling?

We have a 2001 F350 Super Duty for hauling stuff. The Tacoma is a fine mini/midi truck, but above ~500 lb in the bed I begin to worry. The comparison between the relative sizes of the running gear between the Tac and the 350 is instructive. The GVWR spec is conservative, but honestly look at the underpinnings of the Tacoma and realize that it is *not* a heavy-duty hauler.
my $0.02.

 

About 40 years ago I drove 50 miles with approximately 3,000lbs in my F100 with helper springs. Half way home I was going downhill it was fairly steep, speed limit was 50mph. Thought I was being very careful leaving lots of room in front of me etc. At the bottom the hill the signal turned red. I pushed the brake peddle the truck wasn't stopping, pushed harder it wasn't stopping, push even harder with hardly a change, then I was using every ounce of strength I had and the truck was barely slowing. I really thought I was going to blow right though the light at high speed. It seemed impossible but somehow the truck stopped in time. No squealing tires, not even a peep.
I honestly don't know how I got it stopped, maybe some adrenaline kicked in and gave me more strength???

 

Most of the year my 2012 AC weighs right around 6000 pounds with armor, tools, and upgraded suspension, tires, etc...

Then I hook up the trailer to haul logs and brush.

The reason these trucks are so great is their versatility. Just do the right mods for your uses.

Without a tow package, the towing limit is 3500 pounds. Considering this, you are well within the capabilities of your brakes. Your suspension is the real concern. AALs, airbags and such don't solve the real weakness here - the stock leaf springs. Get a leaf pack from OME, All Pro, Deaver, or another quality spring company.

 

I recently had a similar dilema. I needed to get 1,600lbs of landscaping brick quite I distance. I got a trailer. Which worked out because I ended up getting even more stuff.

I would not pack in much more than 1300-1500lbs in the truck at a time for short trips. Obviously no long hauls. Even then you might want to plan for your leaf springs going flat. These trucks really aren't made for heavy duty truck stuff without modification.

 

It's a lot more practical than the alternative.

I found a lightly used 5'X10' trailer and paid $600 for it several years ago. One of the smarter things I've ever done. I can put double the weight in it that I could haul in a 3/4 ton truck and pull it with my Tacoma. I also have an F-150, but I'd still use the trailer for those type of loads even if I owned a 3/4 ton dually. Everything is easier. Loading, unloading, and it doesn't beat up the bed.

Upgrading the suspension doesn't do a thing for your brakes and other components. These are LIGHT duty trucks, don't try to turn it into something it wasn't designed to do.

 

I would carry a ton on my 91 pickup no problem. The rubber stops were not touching yet either

 

Given some folks' tendency to sue at the drop of a hat, I would not take a chance of an accident while driving overloaded. I'm not sure what my insurance company would do under those conditions. As a minimum, they would most likely raise my rates.