Tighten side mirror

SOURCE: 02 Lincoln Driver Side Mirror Loose, How To Tighten

There is a soft metal backing on the mirror mount that is bent out of shape - in order to get it right you must remove the door panel. Once the door panel is off you will be able to see the three mounting bolts for the mirror - remove them, once removed you will be able to take it off to straiten the metal

SOURCE: MY 2004 NAVIGATOR MIRRORS JUST MOVE SLIGHTLY ON

get a mirror switch also. and anything else that you think you can use.

SOURCE: Replacing spring mount in side mirror

I would probably just see if u can find another one from the salavage yards. Not worth the time fixing it.

SOURCE: side mirros not working correctly on 2003 navigator

Most likely will have to replace them
& doubt they are inexpensive,so much so,
I'm afraid to call & ask for my own

SOURCE: I havbe a 1997 town car signature series that the

They make the mirrors with several styles of fasteners. Usually there is a screw "plug" called a set screw. This usually has a Hex shaped recess in the part and you simply insert a Hex key and lightly snug the set screw by turning it clockwise like most screws you would be tightening.

The reason I said "lightly" is that the part that is on the windshield is glued on. They are forever coming detached from the windshield. So reefing on the set screw will probably cause the glue to fail. It is better to have to tighten the mirror several times a year than to have to get a glue kit and remount the base to the windshield.

There is also a mount which depends on a spring tab beneath the mirror to lock the assembly in place. If you have this type of mount, it is not adjustable. But you might be able to put a drop of glue on the surface seam to take out the rattle and the mirror should no longer vibrate.

I hope my info helps you.