Crank arm loose (squared taper). Can it be fixed? My problem is that my squared taper crank arm keeps on coming loose no matter how hard I tighten the bolt - it also starts creaking.
Here’s a video of the problem
https://giphy.com/gifs/RlN0wNSZsWluF5izKz
I’m thinking replacing the crank arm would do it since it seems to have become larger than the axle. But I’m curious: can this be fixed somehow?
Edit: I’m thinking the whobbliness is normal since the bolt is suppose to tighten it against the axle. But the problem is that the axle has come all the way through the space for the arm, making it impossible for the nut to squeeze it against the axle.
Here you can see the axle coming all the way through the arm. Is this normal? Shouldn’t it stay inside so the nut can squeeze it against the axle?

Ideas if this can be fixed? I’m thinking that a new axle could also have the same issue
Edit 2: I’m thinking perhaps a washer that is as big as the crank hole walls could push towards the axle?
This question about loose crank arms has been asked and answered several times before on this site, but yours is the worst I've ever seen I think.
Unfortunately your crank arm is ruined. If the alloy crank gets loose and is ridden on the hard steel spindle wallows out the relatively soft alloy. It does not matter how tight the retaining bolt is done up the deformed crank arm will continue to come loose.
Replacement crank arm (or both crank arms) is the only solution. The bottom bracket and spindle are probably fine (unless the bearings are worn out).