She's fixed! Share my joy!
I want to thank Brain and all the other posters. The shift motor overhaul information here (and in the Singleton thread) is excellent, better than any shop manual.
I fixed mine this past Sunday. It was the classic problem: The plastic bushing was shattered into lots of tiny pieces, some of which got ground up in the gears. I replaced it with the suggested piece of fuel line and cleaned the motor commutator and the position sensor contacts.
I got it all back together and tested, just as the first few snowflakes appeared. As it turned out, I didn't need 4WD, but when I got to work on Monday, I did a few victory laps in the unplowed part of the parking lot. I made some nice alien 4-wheeler crop circles
It even seems to shift into 4WD faster, with less delay.
Cost of hardened T-20 security Torx bit (my cheap one twisted) $5.00
Cost of fuel line: $0.00
Sound of 4WD engaging (click, click, clunk) and sight of "4X4" lamps: Pricless!
Brain, et al, I salute you
Bob