aka "pin" weight,

How much is too much for a W250 with the stock rear axle and 235/85 R16 "E" tires? I'm guessing 2,000 is a good number but am not sure.

 

Let me rephrase my question. What's the max payload I can put in the back and drive long distances at highway speeds and be safe?

 

You worry to much. Run it. If it will stop, your all good.

 

Mine sits at 1600 on the axles.

 

Just doing research. I'm not going to overload my truck.

 

Tongue weight would depend on trailer size and cargo, of course. The 2003 33' Tailgator my dad owned a few years back had a tongue weight of only about 1500lbs. That's nowhere near the payload capacity of a 3/4 ton.

 

Assuming the trailer brakes work properly .

 

5th wheel pin weight is about 10% - 12% of the total trailer weight.

Unless you've got a really huge trailer your guess at 2K would be pretty close.
I ran an '81 and an '87 Dodge D250 pulling 5'ers and never knew the trailer was there - except when I tried to stop...Distances were longer - not scarier.
The 5th I pulled with my '87 was a King of the Road 40' and grossed at 18,750 which I consistently ran overloaded. Most I ever weighed it at was 19,525 and the '87 yanked it around without much fuss.....OH - I did have a 440 with 4:11's.