After being stuffed inside one of the animatronic characters, you’ll hear loud clanging and the female voice ranting about “something being wrong on the inside" before she removes the face plate.
This is where it gets tough: you need to keep the marionettes and minireenas from killing you by tightening the spring lock bolts on the right and left sides. When they go red, the locks are about to break and you need to tighten them immediately.
You will lose track of the number of times this happens
Ideally you don’t want any of them red, but if five or more are red at the same time you get the death screen. The locks are fully tightened when the white dot is all the way at the top-center point.
While tightening the locks, tap “A” and “D” to wiggle back and forth, which knocks the marionettes off you, but also loosens the locks more. This makes for a tense back and forth where you have to decide when to wiggle and when to tighten based on how far an enemy has gotten up the sides.
You have to work very fast to tighten the locks
In the best case scenario, you should wait until they are all tightened before shaking, but be sure to keep looking on the left and the right repeatedly while you work – if you aren’t paying attention, one of the crawling enemies will get to the top while you are tightening on the other side.
The game doesn’t make this clear at all, but you can actually ignore the enemies coming up the center. You just have to shake loose the ones crawling up on the left and right sides.
Ignore the middle one and shake off the “X” marionette on the left
The side marionettes crawl at a slow pace, so make sure all your spring locks are tightened before you start shaking. It will take a few tries, but when you get down the groove of tightening on one side, shifting to the other, and shaking just before the kill screen, you will eventually pass this insanely hard FNAF Sister Location night 4 puzzle!
Still can’t beat it even if you know the mechanics? You aren’t alone - there seems to be an element of luck here. If you want, you can always just cheat and skip the level.