I've only once resorted to use super glue to fix a transformer, that was with 2007 movie legends Ratchet. His upper thigh hinges were driving me mad due the fact that they were already losing their stiffness in less than 20 transformations.
-First i spread out his legs about 45° while in car mode so they pointed to the sides.
-Next i carefully applied glue to only one leg first(just to focus on only one leg during the next step) and inject the glue as close to the body/underside of roof between the legs where the hinge is.
-Let it sit for 3 to 10 seconds, the carefully twist the hinge into the desired
direction while even spreading the glue, give it very rest for while twist the hinge some more until you feel its tight enough.
Then repeat steps 2 and 3 for the second hinge. if done correctly the affected hinge should regain its former strength or become even stronger than it was if it supports a heavy part.
I don't know if this technique would works for balljoints if i apply glue, twist the limb around the ball, the quickly pull it off for a while then press it back on and test the sturdiness. so far i've been reluctant to use this on balljoints but if anyone has good advice for balljoints then i'd appreciate it...i have 2 versions of movie bumblebees that are starting to lose their strength in their balls.