Is there a way to tighten down the glass of the outer car mirrors?

I can see them flopping up and down, when I am at freeway speeds of around 70 to 80 miles an hour.

I checked the houseing on the drivers side and it is loose, but the mechanic said I will have to replace the whole assembly. I am not convinced that will fix my problem, because the passenger side mirror assembly holds tight and does not move when wiggled with you hand. but the mirror still flops around.

Just want to get opinions before I drop 400 bucks on the drivers side assembly.

besides the flopping at freeway speeds, the mirrors adjust and the assembly folds in and out. the fluttering is just annoying.

have you tried to fold them back using the foldback feature on the mirror adjustment switch? try doing this several times, and see if they tighten up.

It is not the outer assembly that wiggles at driving speeds it's the glass itself.
the mirrors move or flutter up and down like someone was flipping the mirror adjust switch really fast.

Even though the outer assembly on the driver side is loose I will try your advice to tighten it up. the mechanic could not see a way to adjust the gear assembly to get the outer assembly to self tighten.
I must admit he almost gave me a heart attack when he had folded the mirror assembly in and out by hand.