96 XLT. Today I noticed that my passenger sideview mirror is vibrating whenever I drive, not just the mirror but the whole housing. At first i thought the screws that hold it to the door were loose but they aren't. The door skin all around where it mounts to the door moves if I push on the housing. It's as if whatever the side view mirror housing screws into is broken. Does anyone know what the mirror screws into inside the door? The drivers side mirror is rock solid, doesn't budge at all.

 

Aftermarket doors are thinner sheet metal and often allow this. My 93 has had the driver's door replaced with an aftermarket unit and the mirror does the same thing. Inside the door there is a backing plate that helps reduce this effect in the OEM doors but its not as much of a problem with the OEM doors.

If you are certain the passenger side door is an OEM unit, then you might check to make certain the backing plate hasn't rattled away from the bottom of the mirror flange on the inside of the door.

 

I had the same problem with my 94 drivers mirror. While putting front speakers in I noticed a bolt behind the door panel for the mirror that had loosened up. Tightened the screw now it doesn't vibrate any.

 

Thanks for the quick replies. If the door isn't stock they did one heck of a job replacing it and matching up the paint. The original owner told me it never had so much as a small dent anywhere on the truck so I'm pretty sure its OEM. I'll have to call the original owner and ask him if it's been replaced if I can't find anything loose inside.

I need to replace my speakers too. Guess i'll have a look around when I'm in there for anything loose. By the way... what size speakers are in the doors?

 

Should be 6" diameter rounds.