Thanks, I'll definitely keep that in mind with you having success. I bit the bullet and bought and installed two shfter knobs from a Toronto Volvo dealer with a web discount and free shipping. I'm saving the best of the two old ones and a couple of its loose chunks as a spare to be repaired in case one of our dogs ever decides they're a chew toy.

I found an easy way to get them off if a few good pulls up don't work. At the top of the shaft, on each side are a small metal stud that engage into small plastic slots inside at the top of the handle. That's what's holding them moreso than a friction grip on the shaft as I had always assumed. Do a sudden pop straight up using a long handled pry bar leveraged against a small square of plywood layed across the sides of the console. Carefully insert the tip between the square plastic collar below and the base of the knob handle, push the collar down to gain a slot. The collar can be a bit brittle and there's a tiny lip up into the base of the handle that can get chipped, so keep it pushed down as best you can when inserting the tip. The base of the knob is quite solid for prying, both new and old handle knobs. Pry at the sides or at the corners, not in the middle where you can tear into the OD cable and wire insulation if you're not careful. Poke your fingers though the fibre comb to know where the cable is. (Why do I know this, said he rhetorically, having needed to use heatshrink to insulate a badly nicked wire.) A couple of really good pops and it should fly up and bounce off the roof like a rubber bullet. Do not have your head above the knob.

Of course the OD switch needs to be pried out and disconnected first. Elsewhere it's suggested to cut the OD wires close to the switch. There's not much slack so every mm of wire you leave, all the better. They actually easily unsolder with the touch of a fine tipped soldering iron. A hemostat can be used to clamp and hold the ends of the wires out for re-soldering. Tin a bit more solder on the wires as needed. The tricky bit is grabbing the ends of the wires just before you finally slam down the handle over the studs, otherwise the wires can fall back and be inaccessible or even pinched between the knob and shaft. I think it was Spook who suggested using thread to keep the wires pulled up and out. I didn't have thread handy, so managed using trial and error.

Doing the second knob a couple of weeks later was a piece of cake except there was very little slack in the wires for re-soldering the switch no matter how much I tried to get a litte extra from below. I'd have needed to half-disassemble the shifter assembly to feed more cable. I've needed to disassamble shifter assemblies a number of times, a non-trivial job that takes time and a fair bit of trial and error to figure out the first time. To lift the assembly up so you can remove the shaft and lower lever to lift the shift lever up a bit to feed more cable, I'd have needed to start underneath disconnecting the trans shift lever and OD solenoid wire. Removing one or both console side panels can help make things more accessible. Getting at the shift lock solenoid and microswitch is even tricky. In one caae, the microswith one of mmicroswith platic mounting pins was broken, to be replaced by a long thin screw. In another case, I decided to rip out a troublesome solenoid that didn't always want to operate freely -previous efforts didn't last long.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Yes, I've always thought that body oils and hand cream were a significant part of the problem. Initially it's the surface that starts to suffer where the palm of the hand rests, so keeping it clean and perhaps using Armorall should help extend the life of the knob. But when the chunks start falling off the front edge it seems the damage goes much deeper than what could be absorbed.

Right, that breakable plastic strip. Those 900 AW transmission shifters can become a real nuisance as the car ages. In 240's with a similar shifter box and trans linkage, they can generally be expected to last the life of the car only needing the odd indicator bulb and eventually a gear selector neutral safety switch. Plus of course the occasional do-nut linkage bushing. The 700 shifters are somewhere in between. In our two 940s, an increasing problem for me in recent years. The shifter assembly changed for '94/95, making them even more complicated to work on. So far in our daily driver 940: neutral switch twice failed (plastic retainer studs easily break getting the push lock washers off), two shift indicator blinds (as Volvo calls them, tails break off, major PITA to replace, little square bulb window easily lost and not included with the replacement blind, need to remove NSSw to access, difficult to mount without breaking again), three bulbs (mild PITA to access), bulb holder wires easily break during handling, stuck park lock solenoid (late models only, major PITA to get at, removed in disgust, associated cable to ignition switch also a nuisance), gear shift knob (deterioration), mounting tabs for the top cover easily break, shift lock override plastic stick easily breaks. I'm sure there's more. My other 940 hasn't been quite that bad, mostly because problems occur first in the other car and I've now had practice with how to get at things and not break stuff. If needed, I can now disconnect and fully remove an entire shifter assembly in maybe 25 mins -well over 2 hours the first time. NSSw is now easy to get off as I always replace the push lock washers on the thin plastic studs with acorn nuts. And who decided to move the OD button low on the back? -no label to give a non-900 driver a clue. At least the new gear shift knob I just got looks like better material.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Thanks, Spooky Jay. Salutations and best wishes right back at you.

That's good you confirmed my suspicions about overall degradation of the polymerized rubber and not being able to get glues to stay bound. Further adhesive attempts on my #2 knob will thus likely be short lived at best, as I rather suspected. Time to break open the piggy bank again and buy another one.

You say a violent upward yank for removal. Guess it wouldn't hurt for me to spend a few hours reading world political news to get me frustrated and in the mood for violence. Art has an easier and more sophisticated method for 240s involving 2x4s and leverage that I once thought would work for our 940s. If a few good yanks don't do it, I'll probably go straight for the razor knife to slit it up the front and peel it off.

I was going to cut the OD button wires off leaving a couple of mm of bare wire for later soldering. The reason I mentioned hoping for enough wire slack was that I've had the entire trans shifter assembly apart before (not something I recommend as reassembly is difficult) and hope I left the original amount of slack at the base of the column. I'm fairly sure I would have as I'm quite aware of removal, even had one out once when dealing with the shift lock tab and wanting access from the back so I could hold the rod with needle nosed pliers.

Interesting comment about the gearshift knob still being in the parts chain. You're quite right, if there's a part that's likely going to be NLA, it's that kind of part as many will never need replacing in the life of the car, especially those parked out of the sun. Perhaps it started to become a known issue and they stocked up on extra before the end of production. More likely, it's easy to slip an order for just 50-100 of them alongside a larger order for newer model gearshift knobs. It may be fairly easy to dig out the old mold and stick it in the same manufacturing line, hopefullly using a better compound.

Wish that was true for the larger '95 (and '94?) 940 fuel tank pickup assemblies that I'll soon be looking for. Hopefully my local yard has a later 940 with one.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now