Steering wheel clunk

The last few weeks I had noticed that once and a while the steering wheel made a sort of clunk, usually when the car started moving while turning (like turning right at a stop sign). Well, today I also noticed that I could lift the wheel slightly, and when it released it made that clunk. Apparently sometimes I was putting enough upward force on the wheel to lift it and then it would clunk back down. The adjustment lock lever seemed to be completely closed, but it was opened and closed again, and the wheel could still be lifted the same small amount. So I pushed up pretty hard on the adjustment lock lever, and while it didn't seem to move at all, the steering wheel could no longer be lifted at all, and so far no clunks.

This is a new one for me.

I have only adjusted the steering wheel height a handful of times, once to set it when we bought the car, and the other times to get it up and out of the way more in order to work or clean under the dash. The last time was a couple of months ago. It probably was moved by the service department when the combination meter and evaporator were replaced years ago. That isn't a whole lot of use, certainly not enough to expect any wear. Even if it was wear, how could the mechanism lock better without having a perceptible displacement change?

Anybody else seen this?

Edit: Note, the position where it could be lifted up was not all the way down, and the current position where it cannot be lifted, is not all the way up.