How do I release the rear view mirror ancho?

[Human]

So yesterday, as I was putting the top up on my CS convertible, the rear view mirror decided to drop off of the windshield just as the top made its final touchdown. I got one of those little adhesive kits, which I've used many times, but I've got a slight conundrum this time. The little metal anchor is firmly attached to the mirror and I don't see how to release it. There's a little slot at the bottom, into which a screwdriver will fit but once in there, I don't feel anything to push, twist or pry to release it. I checked the factory service manual and it shows the mirror held in with a set screw. Mine doesn't have a set screw. Any insights would be welcomed and appreciated.

Edited August 31, 2019 by Human

[Human]

Okay, I solved it. The little slot turned out to be a red herring. The trick is to pry with a flat tip screwdriver from the top, curved end, rather than from the bottom where the slot is. So I've now got the anchor stuck back into place on the windshield and I'm waiting for the adhesive to cure so I can actually put the mirror back on the anchor.

I briefly considered replacing the original mirror with a self-dimming, compass mirror that I took out of a '99 Park Avenue a few years ago, but the electrical connectors are different and it would have meant losing a significant part of my working interior illumination since the dome lights on the faux roll bar don't work.

If it were a little cooler out and I were less busy today, I'd take it out for a celebratory drive. I'll be driving the car for a couple of days next week, regardless of the temperature, since my Impala will be in the shop getting some minor repairs done. I just hope it doesn't rain before I get the Impala back since the 'Vert isn't all that weather tight. It also doesn't have working air conditioning, so It'll be a little uncomfortable if the temperature gets above about 84 degrees. 

[Human]

So a few minutes after I made my second post, I tried to put the mirror back on the anchor button and the button promptly came off the windshield! I went back to O'Reilly, where I had gotten the adhesive kit and the guy behind the counter was very nice about it and gave me another kit at no charge. I went through the whole process again, cleaned everything off and re-attached the anchor button. Even though the instructions only call for 30 minutes curing time, I'm letting  it cure a full 24 hours before I try to put the mirror back on. I've done at least 10 mirrors like this and I've never had so much trouble one mirror on.

I was reading online that Ultra Grey silicone can be successfully used for this purpose. Prep the windshield and anchor button as you would for a regular adhesive kit, then put a dot of Ultra Grey on the anchor button, mash it onto the windshield and hold it in place for a couple of minutes, then tape the button down with painter's tape for about 24 hours before hanging the mirror on it. If this second attempt with the adhesive kit fails, the third time with Ultra Grey may be the charm.

[Human]

Looking back at the beginning of this thread, the adhesive lasted a little more than 13 months. The mirror dropped off again Monday afternoon. Same scenario. My convertible top comes up slowly but then drops hard onto the windshield from about six or eight inches up. The impact is enough to jar the mirror loose over time.

I'm a bit frustrated with the $4 Permatex windshield adhesive kit I got from AutoZone, which is the same one I used before. A year ago, it took two tries with two kits to get it to hold and when the mirror fell off again Monday, I noticed the adhesive still felt soft and rubbery, having never fully cured. I got another kit and tried to put it back yesterday. The instructions said to let it cure for half an hour and after last year's experience I allowed an hour and a half before trying to reinstall the mirror. but the adhesive let go as soon as I started to push the mirror onto the anchor.

I'm not sure what my next step is going to be but I'm tired of throwing money away on those Permatex adhesive kits. After re-reading my posts above (wish I'd read them earlier), I 'm thinking of trying the Ultra Gray Silicone. The tube is already on hand so I've got nothing to lose. Anyone have any other suggestions? Frankly, I miss the mirrors on the VW Beetles I had in high school that just snapped into a recessed bracket in the ceiling, right above the windshield. Like everything else on those old classic Bugs, it was elegant in its simplicity.

[oldmangrimes]

Aside from the adhesive issue, your comment reminds me of the old story when the guy goes to the doctor and says "hey doc, it hurts when I go like this" and the doc says "well then don't go like that".    Meaning, maybe change how you close your top.   On my old top, it would slam if I ran the motor the whole time it was raising.   I learned to stop the motor when it was ALMOST closed and let gravity finish the job gently.   Also I'd raise my hand and catch the front of the top to cushion the impact as well.

Now, with my new top and new cables, the tension is such that it doesn't slam, but it may start to over the years as things loosen up and the cables stretch.   Anyway, I know each top/frame/cable combo is different, but maybe there's a way to close yours more gently.   Also, the pin cups can be broken from slamming the top closed as well.   

[jiggity76]

I've never had good luck with those kits.  I take my vehicles to the windshield glass replacement shops.  Never had an issue of them falling off after they did the repair.

[Human]

1 hour ago, jiggity76 said:

I've never had good luck with those kits.  I take my vehicles to the windshield glass replacement shops.  Never had an issue of them falling off after they did the repair.

Yeah, I've never had this much trouble putting a mirror back up. The kits always worked fine for me up until now. I think they used to make the kits better back a few years ago. The EPA probably made them remove some chemical that made it work better. Wouldn't be the first time. I've also noticed they're harder to find now and there's less variety. I may end up taking it to a shop but I'm just kind of ornery sometimes and feel like I'm being foolish if I pay somebody to do something I am perfectly capable of doing myself, especially something I've done before. I think I was at a very impressionable age when I read Thoreau essay "Self Reliance" in high school. This afternoon, just for the hell of it and because it didn't cost me anything but a little time, I cleaned off the glass and anchor with acetone and put the anchor back with Ultra Grey silicone. I'm letting it cure until tomorrow afternoon or maybe Friday before I try hanging the mirror again. If it doesn't work, I'll re-evaluate the situation and consider a glass shop.

Edited October 7, 2020 by Human

[Schurkey]

Cleaning-off (removing) the old adhesive is a good plan.  I typically use a single-edge razor blade on the glass, and a wire wheel on the metal tab the mirror mounts to.  The old adhesive has to be G-O-N-E before the new adhesive has any chance at working.

Grey RTV Silicone?  If it works for you...fine.  I've never had a problem with the rear-view mounting kit, but if I did, I'd use super glue.

No set-screw?  Really?  I think every mirror I've dicked with has had an Allen-socket set screw.  Without the set screw, the mirror is loose on the metal tab--wobbles around.  The set screw keeps it firm to the metal piece.

 

[Human]

My cleaning method is to soften the glue with acetone, then scrape it away with a razor blade or pocket knife, then sand the anchor button with coarse sandpaper (80-100 grit) to roughen the metal and give a better adhesion surface.

I remember the set screw on GM cars from the '70s and '80s but somewhere in the '90s, GM got rid of the set screw and went to a tension fit system. The first car I encountered that on was a '97 Olds Eighty-Eight and I've also seen it on Auroras and full size Buicks and Cadillacs as well. In fact, according to GM service manuals from the mid-late '90s show the prescribed method for removing a mirror is to grip it with the left palm facing the glass of the mirror and the right palm to the back and snapping it off by pulling the right hand sharply away from the windshield while holding the left hand as stationary as possible. The only problem is you sometimes take a bit of the windshield glass with you, as I noticed when I acquired a compass mirror for my '95 Aurora.

The tension fit anchor is somewhat problematic because it takes considerable force to get the mirror down onto the anchor button, often it is sufficient to break the bond between the glue and the glass. In some instances, I've secured the button onto the mirror and then glued the whole thing back, holding it in place for about 15 minutes to give the glue a chance to set, which is really painful to the arms but the installation is generally successful. Just thinking outside the box, I've got some 3M double-sided trim tape that's supposed to be able to support 100 pounds. I wonder how that would work. I doubt the mirror weighs more than a pound or so.

[Human]

So I re-attached the mirror to the anchor a few minutes ago. So far, so good. It's holding better than the Permatex kit did to the pressure of pushing the mirror back onto the anchor. The Ultra Grey silicone dries much harder than the clear or black silicone. I'm getting ready to take the car out for a little run and we'll see how it does long term.