I pulled into a parking space at the movie theater, opened my door to get out and it stuck partly open. Those of you who have had a stuck door know the feeling.
No tools with me of course.
I found a can of WD-40 in the back and drenched the mechanism through the hole in the door. Freed the door to close.
The balls are no longer engaging, the door swings entirely smoothly from closed to full open. Having disassembled one of these before, broken springs stuck in the grease often jam the mechanism, preventing the balls from moving. The WD-40 must have melted the grease and loosened the broken pieces. I'll let folks know when I r&r.