looks like a lightening strike ... no clue as to the health of the remainder of the tree based on these pix the green stuff is lichens .. ignore ken

I don't see the source of any confusion...but too clarify... A single modestly sized branch has bark peeling. All branches downstream of it appear dead, and either have no leaves or shriveled dry leaves. There is one branch, immediately downstream of the afflicted branch, that still has healthy leaves on it. I'd prefer not to remove a "struggling" branch, since all the leaves are fine, and the branches are large and would constitute the removal of a sizable portion of the tree. I can remove the one branch with dead leaves, as it certainly appears dead, but cutting it off upstream of the split bark, means removal of a side branch that is still healthy. All other branches on the tree that have peeling bark, have no sign of dying leaves. There are other branches on the tree, which do not have any peeling bark. Other observations and notes. The bark is not being chewed off. The bark is developing splits which then open up, and the bark curls away. In January or thereabout, it became extraordinarily cold here, down to perhaps 25, though the weather report said in places it reached 22. We had an early spring and the tree popped with leaves pretty early, and then it got cold again, but not freezing. The peeling is only on the west side and only afflicts branches near the top of the tree. Nothing else has changed with the tree. Sorry, I don't know what the local extension office is. Phil

Syringa pekinensis (Pekin Lilac) can develope exfoliating bark similar to A. griseum. Small tree along the lines of Japanese Tree Lilac. I've heard there's an impressive specimen at the Morton Arb, but haven't seen it myself.

I may be judging some peoples thoughts on here unfairly, and maybe I'm the one who's wrong. But, Not all trees are symetrical and perfect. Trees get burls,galls uneven growth if one side is shaded etc. Some times your mulch gets dog vomit fungus and your tree gets Slime Flux. It isn't all perfect, but, it's normal, and no cause to just throw it out and start new. Yes, sometimes you need to get rid of a diseased tree and start with the new, but, I just don't see this (the Op's) tree as a lost case to get rid of. This is likely why ( at least in the US) there won't be many old tree specimens to show future generations. I realize if there is an old tree near a house ready to fall it should be cut down, but, the younger generations (no I'm no crotchety old man) will just get rid of trees that are breaking down, even if they are away from buildings. In the UK, it seems they remove any rotten wood, then fence around them, so nobody will get close enough to get hurt easily. Then the tree continues to put on growth in girth, if not height, and it is a sight to behold, and of great age. I need some unicorn blood to make sure I can be around and make sure nobody cuts down my English oaks and white oaks. I'm kidding about that of course. I don't mean to be ignorant to Logan and anyone. But, trees get better with age, and don't need to be perfect, they are shaped by their environment. In the forest they don't have limbs until many feet up in the tree because of growing in the forest environment. I guess if you are in a HOA neighborhood, and all has to be perfect, you will think if it isn't perfect it has to go.