Loose Side Mirror(Glass)

I drive a 92 SL2. My manual drivers side mirror has a bit of vibration to it and tends to point downwards after a while... Can anyone suggest anything to help tighten it up? Perhaps there is a way to make the ball joint stop shifting so much?

Thanks.

if the actual adjuster or mirror isnt loose from where its suppose to be, id say its just worn which sounds to be the problem.

Well, is there anything I can do to tighten it up? I know when something doesn't move, and it should, wd-40 it, when it moves and it shouldn't, duct tape it... So, is there anything other that I can do than duct-taping, lol?

well the glass sits in a couple pivit points. once they are worn, i dont know of anything to fix it other then replacement. i know mine drops ever so slightly after a while and i have a 97. it may be a bit different issue, but i couldnt say since im not there to look, but my only guess is that its worn.