Nothing in the photos you've shown give me any inclination that this tree is dying, or even in distress.

Is this a fairly new construction? That tree is awfully close to the driveway and house - and that large limb that was removed looks as though it would have been protruding right out into the driveway. Makes me wonder if the tree was there before this housing development went in...

Additionally, for that size tree, there's not any root flare showing, making me wonder if they added several inches of 'topsoil'; scads of folks here get all gaga over root flares and 'telephone pole' planting. It's an issue for many species - but pecan, being a riverbottom species, is less bothered by, and adapted to dealing with frequent, periodic depositions of silt during flooding...so, perhaps not the issue it would be for other species.

Is it a hazard? We can't tell; you'll need the opinion of an ISA-certified arborist - not just some goomer with a chainsaw and a chipper.
I've seen big old pecans & oaks live for decades - or human lifetimes - with big open wounds into the heartwood
Trees drop leaves. The little pecans dropping may not have been pollenated, may have been infested/infected by pecan casebearer, hickory shuckworm, pecan weevils,or pecan scab and may be being aborted. Or...drought stress may be causing premature leaf drop and nut abscission - but the photos you've posted show what looks to me like a healthy pecan.

The home is new to me but was built in 1951. I'm not sure if the tree came first or the driveway. The driveway is really cracked and sunken in places probably due to the soil - it's very expansive clay. If I had to guess I'd say the driveway was there before the tree because I would think that the tree would've been killed by having a driveway poured over the roots.

There isn't an ISA-certified arborist within 100 miles of here unfortunately - that was the first place I looked. There is no shortage of goomers with chainsaws though (but I have yet to see one use a chipper.) In the month that I've lived here I've had at least 4 tree-trimming crews come by and another 5 or so leave cards at the door.

The part that I am most worried about is the soft tissue around edges of the pruning scars - especially because it's so low on the trunk - I wonder if it isn't spreading deeper into the tree.

Nah, I'd expect a 1951 model pecan to have a significantly larger bole than that. 1970-era pecans in a good site here are so big that two people can barely touch hands reaching around them.

Those were LARGE limbs at the time they were removed, some years back - way too big for the tree to cover over before the potential for 'rot' moving into the exposed heartwood set in.
That said, in and of themselves, those are not necessarily, IMO, reason to remove the tree - most of the 'structural integrity' of the tree may still be intact.
But, I don't even play an ISA-certified arborist on TV, so if you're worried about it as a potential hazard, have it removed - just don't let the chainsaw jockeys top it.

Lucky or anyone, what made all those holes in the 2nd and 3rd pic? Borers or woodpeckers? Just wondering in case I ever see that on a tree in the future.

My guess would be something like powderpost beetles.
Have a couple of pecan poles, from some 15-ft seedlings I cut down for wood to smoke meat with, that are just leaning up against the back of the house - now riddled with ppbeetle holes similar to those in the photos, and their sawdust dropping down onto potted plants nearby.

i wouldnt have that thing hanging over my house ...

did you talk with the tree surgeon ??? .... or just presume 100 miles was too far ...

there is no real hurry.. i would tell the TS to put me on a day.. when he will be in the local area ... even if it took a month or two to get there ...

are you in any given storm area of TX??? .. its kinda big to make presumptions ... twister area... hurricanes... etc ...

if poaky wants to camp under it.. all the power to him ... i wouldnt look at big gaping rotting wounds.. and think... wow.. this is a safe haven ...

in fact.. it would be gone in as short a time.. as it took the chainsaw monkey to schedule me up ... its a hazard.. not a pecan ... IMHO ... and i wouldnt bother with the arborist .. you have two wounds in the first 5 feet ....

research proper planting time for your area... and be prepared to plant some new trees ... at your new house ... in with the new.. out with the old ....

ken

Ooh, thanks for answering that lucky (and poaky for asking). I have seen some woodpeckers on occasion but not on that tree. I had assumed that it was damage from shothole borers but had never seen any bugs like them. However, I looked up the powderpost beetle and I have definitely seen some of those in the yard.

Ken, I haven't talked to a tree surgeon. The closest one I found was 160 miles away. I can't imagine she would travel that far on a regular basis. I'm also not prepared to pay hundreds to thousands of dollars at this time (for this tree and some others I have concerns about.)

And yes, we've had hurricanes in the past.

It could stand for 100 years - or fall tomorrow.
It's a bit close to the house for my liking, with those big wounds and the dual leaders - which actually bothers me more than the open wounds.

I can't ever recall a case when someone posted question like this that ken didn't think was a hazard that needed to be removed yesterday ;>), but this is one even I might consider having taken down.

Ken, have you been drinking when you made that post? You may have been, because I only asked what made the holes, because I have just added a baby Pecan to my yard recently. I made no comment on the tree like that it is likely fine etc. Just what made the holes. No big deal on whatever caused the confusion. I have really made some screwy post do to some drinking and posting. I just wanted to point out that I don't think it is a good idea to wait for the Pecan to fall. I had a Tulip poplar (Liquidambar) removed for much less damage than the Pecan is showing.

I also got rid of a Sycamore with less damage. We all get confusious now and then Ken.