Some what of shot in the dark, but I would quess the idler is binding.
These can cause the sudden release POP.
It won't be the Ball Stud/Sleeve it resides in, UNLESS it has been damaged to where the Brass bushing in binding when the necessary travel is restricted--No need for restriction unless, Some Idiot Pickle forked it.
A Day, 12 Pack, Will get it done with Mechanical Knowledge, Good assortment of Tools.
3 Weeks, Many cases of
, with poor mechanical ability, Buffalo socket set, Multi Screw Driver.
Dan @ Chockostang