Well I did the washer trick and solved the problem with the 2 slotbox 10.
I went sailing yesterday and another problem appeared. One of the screws of the left slotbox 13 never ended to turn. I took it out and noticed the thread was stripped of.
So what do I do now?
I read on the repair guide to use loctite form a thread, but i read some product information elsewhere that staid that it worked on wood and metals not plastic. It said:
"This product is not normally recommended for use on plastics
(particularly thermoplastic materials where stress cracking of the
plastic could result). It is recommended to confirm compatibility
of the product with such substrates."
So I would like to now if the plastic in the thread of the slotbox is thermoplastic or not, and if it is compatible.
Or if you have a better solution?