The 4L60E is a lot like the 700R4, but a lot more efficient in power transfer as well.

 

maudyZ28,
Thanks for the additional information. I'm so stuck in the bad-old-days it's scary. My first thought had been the shift linkage. As soon as the snow melts next week we'll get under the thing and take a closer look-see at the external stuff. I'm getting tired of towing the thing around town and it's at the kid's house (outside) at the moment.
Thanks, again for the info.
COPCO

 

ha ha, thats an advantage us youngsters have as these cars off our generation are run by electronics

The problem is that people get stuck on the fact that there 'are' electronics, but no matter what undernieth there are still mechnical components work all the same as your 'bad/good old days' lol.

 

The 4L60E is essentially a 700R4 that has electric shift controls in the valve body (the 700R4 has a TV cable, 4L60E doesn't). Hopefully, it's just a shift linkage problem where something externally came loose or got jammed. You'll be able to see what's moving, or not, once you get under it. You might then want to disconnect the linkage at the trans and see if the shifter runs through all the gears to rule that out. If the shifter checks out, and you can't rotate the arm on the trans through the gears by hand (or with pliers), then you're going to need to drop the pan and do some looking around. You could have a disconnected linkage arm on a valve body piston, or something else may be broken/jammed within the valve body.