Leroy did you resolve your issue? Perhaps you didn't get any replies because your question is not specific enough. Do you mean there is play in your stem but the fork seems solid? With the front brake applied when you jerk the stem around do you see play between your fork and the head tube? Or do you mean that there is no play but the stem has give when you ride and pull and push on it?
I am sorry that I'm not familiar with the parts and pieces of a bicycle---this is my first----in trying to be more specific, the play or looseness that I see and feel is directly within the locking mechanism holding the "stim or stem" together. When lifting it up and after the locking lever is raised in place----holding the front brake----pushing back and forth-----it is loose----I can see the play at the locking joint.------When I open the joint, there are two screws and a small plate that seems to move into a grove----this seems to be the problem. I've ridden and repaired motorcycles for 45 years, but this is my first bicycle. -----leroy
Does yours look like this pic posted there? Assuming it does, adjust the nut-looking bolt at the yellow arrow. Don't make it too tight or the white plastic block may crack when operating the latch lever. Loctite it after adjusting, they have a tendency to move.
Also, make sure the 2 button-head bolts are not tight, the sliding latch plate must slide freely. Loctite those screws if they are a problem but rather leave them alone.
Let me know if this solves your problem.
 there is another thread referenced in that thread, with detailed pics of the latch parts.