Convertible arms slipping
 

I'm not breaking the plastic ball ends but after a few up and downs, usually the passenger side adjustable arm "self adjusts". I have cranked those securing bolts down but they aren't very big. I do not want to strip the threads. I could put a helper bolt in the slot but I'm wondering if something is binding. However, I have had the top assembly off and it all moves freely. It closes and latches fine but after the arm slips, the clamshell won't lay flush. Any adjustment tips are welcome.

If you look closely at the connection, you can see grooves. This supports the strength of the connection through positive locking. Possibly (and I assume this) the grooves are worn out due to the constant movement. Tightening it more firmly will do little good, probably replace it with a new one or one that is good used. Or try an additional bolt, degrease beforehand. The weakest part is the ball socket (plastic), so don't worry.