Tried a quick search. didn't find a definite answer. I've got both of the capiler bolts/slide pins out on both sides and forgot to check which is which. One pin is round with a rubber collar on the bottom end. The other has flat spots running the length of it with no collar on the end. Can't figure out which one goes in the top or bottom hole. Please help.

 

Rubber collar top.
view attachment

 

onthe3rdday, thanks!