I have a question about transmission leak.
I got stuck in sand, took about 10 minutes of
tire spinning to get truck out of sand.....
when i got out i saw transmission fluid leaking from
where the transmission meets the engine.
when i got home, the leak had stopped, when i checked
the transmission fluid it was a quart low, so i added a quart.
and now it is not leaking.
did i blow a seal or is this normal from over-heating and built up
pressure?

 

This qualifies as "it ain't broke".

You probably overheated / pressured it.

 

When the front pump to torque converter seal gets too hot it gets soft and leaks. Once it cools it usually will still work. It can do several of these hot-cold cycles before it fails completely.

The use you described is a textbook case on how to get the torque converter HOT.

 

What do you do about it? My 2004 F250 5.4L does the same thing when under a heavy load

 

More cooling would help. Change the air to oil cooler for a cooler from a 6.0L truck. Keep the cooler in the radiator in the circuit, too.