zzyzzx wrote:
Try running a diagonal brace from the top of the post to the bottom
of the next post. That will stabilize it in the fence direction;

I really can't do that. It run along the property line and it's the
end piece. It's tilted in, as in towarsd the other gate piece. I
can't brace it to other property. It's for a 14' gate in the back of
a city rowhouse.

Okay, next best thing is to extend the post (possibly replacing it) upwards
several feet. From the top, attach two guy wires: one to the far end of the
gate the other to a post in the other direction. Thinkg of a giant "A".

What you're trying to do is transfer as much of the gate's weight DOWN on
the post with the hinges as possible.

Say the gate is 14' wide and weight 200 pounds. This is equivalent to a
100-pound weight at the end of a 7' lever. That's a huge amount of torque.
With the technique outlined above, ALL the weight of the gate is forced down
on the post and there is no torque at all (to speak of).