78 Avanti II rear window mounting screws and rear view mirror attachment

[davette59]

Does anyone know the size and length of the screws in the rear window trim? The glass installer didn't re-install them when he put the glass back in. I guess, since I won't be going 200 miles per hour, I could just cut the heads off some scres and glue them in for looks. Also, when they installed the new interior, they broke the coupling between the rear view mirror swivel ball and the one on the windshield mount. I cannot find another coupler anywhere. If I could disassemble a new mirror which has a ball attachment I could use that but I don't know how you would remove the ball from the socket on the new one and get it over the old ball. I would much rather remove the old mount and install a new mirror at the top of the windshield but I'm afraid of breaking the windshield by removing the old attachment. Although not a super show car, my car is really looking great (after about $25,000).

Dave

[bezhawk]

The screws at the top of the rear glass are actually machine screws that have a nut on the back side. They also pass thru a steel retaining clip on the back side, effectively sandwiching the fiberglass opening between the glass and steel plate. This is to prevent the rear glass from popping out under higher speeds.
The mirror stems originally were very weak and would not hold adjustment, or bend and break under the tightening of the screws. Later they were upgraded to ones much like the ones used in Ford Mustangs of certain years. he mounting post can be removed from the glass and reglued to a place of your liking quite easily. Just be very careful on applying heat. I take a very fine tip on my torch and heat only the ball for a short time (approx 20 seconds) Then using a pair of channel locks, twist the base close to the glass and it will come right off. Clean up the old glue well, and make sure the base is flat and clean by sanding it with 400 grit sand paper. Use a fresh new rearview mirror adhesive kit. Old kits will not work as well, as they tend to go bad on the shelf once opened. The one time single kits are much better and stronger than the large multi use kits sold to body shops and dealers.


This is the new style and stronger mirror stem and base.

http://www.mustangsplus.com/xcart/1968-73-Mustang-Chrome-Inside-Mirror-Bracket.html

[davette59]

This is great information. Since the silver backing on the mirror is not in very good shape, I will take your advice to try and remove the existing mount. Is there an after market mirror that can be bought to be close to the originals?
also, do you know what the length and thread size is for the screws in the rear window trim? The old screws are missing from when the window was removed and I have no idea what size to buy to replace them.

[bezhawk]

It seems they put long ones in, and then snipped them to length. (on the window screws)
Be careful you don't nick the glass as you install them. A sharp awl is your friend. The metal plates terminate under the rubber inside the car, under the headliner.
Since the mirror stem is a Mustang unit, I bet a Mustang mirror will also work, and you can even get it in day/night style

[davette59]

?I applied heat with a heat gun. The mount wouldn't move and the laminate in the glass started to bubble so I quit. I bought the mount that was suggested and a new mirror from a Mustang site and will re-attach at original location. I would have preferred to move to a higher location but I am afraid of totally ruining the windshield.

[bezhawk]

You can't localize heat on the button with a heat gun. You have to use a very small torch and just heat the tip of the knob, and NOT THE GLASS. You have to do this with one hand, while twisting the base with a pair of channel locks. Twist only, never pry.

[gthawkr2]

If you are talking about the three screws on the top of the rear glass, I just went and pulled one out of my 81 Avanti II. It is #8-1 inch long machine screw. Also, on the rearview mirror, I just relocated mine to the top last month. I tried the heat method with a small propane torch and got nervous about bubbling the laminate so I gave up on that idea. I borrowed some nail polish remover, Acetone, from my wife and used an eye dropper and put one drop at a time on the top and let it run down the sides. Since acetone evaporates very quickly, I repeated about every 30 seconds or so and after 10 or 15 minutes it just fell off. I actually could see from the outside that it was softening the adhesive and I went. Make sure you put some towels to cover the dash and up against the glass at the bottom to catch any that drips or runs down the glass. I did not do that at first, and acetone will eat vinyl. Hope this helps.
Jim