The state of my 40 years old scheffelera is: The bark is withering. When I scratch the bark it is black underneath. One trunk dead one living. Both share a common singular piece of trunk to the roots. My concern is that the side that is living is looking stressed. Can I save it without cutting the dead 'wet' half of the lower trunk?
Just throwing this out there, but a potential option is to do an air layer on the good trunk and then lop it off and repot it. We had a very big one at my work and I hesitated to mess with it, because it had been here as long as the business. It had been in the presidents office and was starved for light. Then thing was almost 6' tall, but leaned at a 45deg angle toward the window. It had a stick in the pot holding it up. I moved it to the break room and it got a lot more light. I fertilized it after a repot (which showed a baseball sized root mass by the way) and I'd let it dry out well so the roots would grow out seeking water. When it put on several new leaves and got stronger, I did an air layer. I let it stay on for about a month, then held my breath and cut it off below the air layer. There was one new growth further down the trunk. I planted the air layer. It took it a month to show new growth on the top, but I planted it up straight and it looks great now.
The bottom recovered much quicker. It's put out 5 new growths, soon to be trunks, and is basically a bush that needs to be whacked back.
Just to further take the stress of you, I had a 12" stump from below the air layer to the first growth. I lopped it off about and 1" above that first growth and after coating both ends in cinnamon and allowing to callous, (I did that with all cut ends) I put it in a 4" jar of water. After 2 months, it had a jar full of roots and 2 leafed growths, and 3 nubs of growth starting. I just had a coworker take it home and plant it.
These are really bullet proof and I would try something like this as opposed to loosing the plant. Good luck.
Edit: There are lots of videos of airlayering on youtube.com, but the basic concept is you create soil like conditions around the trunk of the plant. The plant sprouts and grows roots there. The part in the soil continues to feed the upper plant. Then you cut the trunk below the air layer and pot up the top portion. You now have two plants. I think I did it the hard way. I bought saran wrap and cheap sphagnum mosss from home depot. I made a mess and didn't get enough sphag in the plastic. An easier way I heard about and am fixing to try is to take a ziplock bag, fill it with moistened sphagnum moss, and zip the top. When you're ready to apply, cut a slip in the middle of the bag, exposing the damp moss. Press the bag around the trunk, sinking it into the moss. Wrap with tape to secure in place.
After a short time, you'll see roots. I wait till there are several visible before cutting and potting. If your moss starts to dry out, which it probably won't, cut a small hole in the top of the bag and use a dollar store funnel to add some. The moss will wick moisture through the bag evenly, so add a little and wait to see how far it goes. If you flood the bag, just poke a hole in the bottom to drain. Also, it may or may not be necessary, but I buy a container of cinnamon from the dollar store to coat the cut ends. It's supposed to help with bacteria.
If you watch videos on air layering, you'll see them scoring or removing bark. I've done this process on small and large schefflera and dracaena. I have found you don't need to do that on these plants as they readily root. If you look on the woody portion of the plant, you'll see a ton of little bumps. These are potential roots or potential new growths. Your new roots will easily sprout form these.
Last tip is don't try to separate the sphagnum moss from the roots. Cut away the bag and bury it in potting soil with the moss. Then keep the potting soil damp, but not soaking. You don't want to rot the roots and you do want them to grow out seeking water. I start cutting back the water and lightly stressing them as soon as it puts out new growths. Also, don't over pot. The reason is that if you over pot, the plant can't suck all that moisture up and it can rot the roots. It's better to pot tight and repot as necessary. I did have to pot too big and one of the things I did to help compensate is to that the pothos that grows like a weed in our office, cut it into sections, and push it into the soil. It fills out the pot and helps suck up the excess water.