Sloppy Automatic Shifter on Column - Help!

[steveeg1961]

Help,

As a relative newbie, I'm working through the major glitches with my '72 C10. But one thing I haven't figured out is what is wrong with the sloppy column shifter (3-speed automatic, TH350 tranny). It worked hard before, but then I cleaned up the area where the shifter arm meets the steering column with WD40, and it works very smoothly now.

But in fact, its too loose now. It readily pops down into reverse from park, and doesn't stay in any one spot. There is nothing obvious to this untrained eye as to what is wrong. The linkage from the steering column to the tranny appears to be solid.

So what should I look for? Of course, pics are always helpful...