The video above I have only seen happen at this one arcade I visit and for the life of me I can't figure out why it happens. Lockbars will wiggle, rock, and you can even pry with your fingertips and is MAJORLY distracting during gameplay. It won't happen with newer STERN title's or even older 80's games it just happens to some. I learned in the past the spot welds on some of them had broken and I restored the last lockbar shown in the video. The wiggling ones though still have strong spot welds however the wood grooves for the lock to fit in is getting worn away. I was told by the owner it's because of heavy nudging and nudging in general.
Frankly I think that is not the reason because this is the only location that I have ever seen this happen and that even includes the Pinball Hall of Fame. So how is this happening and is there a way to fix this?