Originally Posted by ecopat
I'm no expert (there is a whole towing section for that, just sayin') but simple math shows that 7771 - 7200 = no.
Apples and ranges. The 7,771 is the max weight of the trailer on the trailer suspension and tongue. The 7,200 is the max weight on the two truck axles, including the tongue weight of the trailer.
First, you need the actual weight of the wet and loaded F-150, before you tie onto the trailer. Then GVWR of the F-150 minus the actual weight of the wet and loaded F-150 tells you the max tongue weight you can have without being overloaded.
Then you need the actual tongue weight of the wet and loaded trailer. The actual weight of the tow vehicle plus the tongue weight of the trailer should not exceed the GVWR of the tow vehicle.
You can determine the tongue weight of the wet and loaded trailer with a tongue weight scale.
Or you can use a CAT scale to weigh the rig twice, once with the wet and loaded trailer tied on (but without the WD spring bars attached), and once with just the tow vehicle without the trailer. Subtract the weight of the pickup without the trailer from the weight on the two truck axles when the trailer is tied on. The answer is tongue weight.
Ford also publishes a "tow rating" and a "payload capacity rating", but those are not very useful. Both are overstated because they do not include the people, tools, fluids, campfire wood and other items you will have in your wet and loaded F-150.
For estimating tongue weight of a trailer, use 15% of the GVWR of the trailer. If the GVWR is not easily available, then assume that GVWR = dry weight plus cargo carrying capacity (CCC) of the trailer.