Just thinking a little ahead here; me and my buddies were thinkin about filling the bed of my truck (short bed, 5.4, 2WD) up with water this summer....effectively creating a 'redneck pool.' That's an enormous weight in the bed
I calculated that if we fill the bed up with 16 in. of water, that would give us 43 cu ft = 336.6 gal = 2810 lbs
So the water plus ~600 lbs of people in the bed puts the total payload at ~3500 lbs, which the door jamb sticker says id the GAWR for the rear.
Having as much weight just in the bed as the whole axle is rated for should be OK right? I mean, it is a ford . Keep in mind that we wouldn't be going very far, and probably wouldn't even go past 10 MPH. You think this would tear up the axle too bad??
I was thinking about doing the same thing. I think you should be fine I have seen people do it a number of times in half ton trucks. I dont know why you plan on driving with all that water in the bed, but I would probably advise against it.
Be sure to use some method the keep the bed walls from spreading apart. Water sloshes and if it gets going while you are moving expect some twisting motion. If ou have a rerar sliding window keep it closed or your cab might get wet.