Is this bad? Rotting?

If i had to bet on it, i would say 90% of it is still solid. The rot usually dont go a whole lot deeper than what you see. Occasionally, there is a deep cavity behind it, not often. Several reasons the water could be seeping out of it, dont necessarily mean anything bad. If you like the tree, and you want to keep it, give it a chance. Pecan trees are not generally bad about being hollow. If it turns yellow and the leaves start falling off, call the coroner.

Looks fine. Was a limb cut off there?

Pecan trees are just about bullet proof. I have a big one in my back yard that took a solid lightning strike about 25 years ago. It's still alive, well and nut bearing

Yes, obviously. I was told once doing a collar cut, or in this case would be leaving a couple inches of that limb on the trunk, would keep that from happening. Never really tested the theory.

I've got to ask, what is the contraption with the spring?

I had one similar, with a larger spring, for my bulldog to hang from.

I thought it looked like a dogs chew toy. Never seen one rigged in a tree.

Looks like Buckscent has been humping your tree. He's been known to hump anything from doorknobs to knotholes. Tends to carry a tube of KY in his pocket. You're tree is a victim.

Yep. For a dog. I don’t think she plays with it though. She’s more content running the fence barking with the neighbors 6 labs, pig and goat. 😂

I know at one time, people would pack spots like that with concrete. If you can dig some of the rotten wood out, it might repair the tree. My dad lost a big pecan tree to a hurricane in 1979 that had been packed with several bags about thirty years earlier after a lightening strike. When we cut the tree up, it had apparently absorbed the concrete over the years.