This article is one in a series that have been released in conjunction with Wayne's book, 101 Projects for Your Porsche 911. The book contains 240 pages of full color projects detailing everything from performance mods to changing your brake pads. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any Porsche 911 owner's collection. See The Official Book Website for more details.
One of the most perplexing tasks to perform on the 911 is the removal of the window glass, whether it's the front or rear window, or either of the side quarter windows. The process is not easy if you don't know what you are doing, however, with a few tips and step-by-step instructions, the process is made much easier.
A few of the projects in this book require the removal and replacement of the window glass. Namely, the replacement of the windshield seal (Pelican Technical Article: Installing Window Glass), the installation of a new dash pad (Pelican Technical Article: Installing a New Dash Pad), and the replacement of the interior headliner (Pelican Technical Article: Headliner Replacement). The process of removal can be quite tricky, so I've dedicated an entire project to it.
All four major pieces of glass on the 911 coupe are attached in similar manners. The front windshield as well as the rear and two side quarter windows are held in primarily by a rubber seal that grabs both the glass and the chassis of the car. It's a very similar system to the one used on the 356. The 911 cabriolet and targa have the same system for mounting the windshield, and the targa uses the same method for mounting and securing the rear window. The rear targa window install is very difficult, and should you should probably enlist the help of someone who has done a previous installation. On earlier 911s with rear pop-out windows, the process becomes even easier as the glass and frame is simply unscrewed from the car.
The first step in removal of the glass is to carefully remove the window molding from the car. The early cars were equipped with chrome window molding that actually inserts into the glass seals. On the later cars, this trim was anodized aluminum. In either case, it is very easy to damage and destroy the molding when you are removing it.
For the windshield, start by taking a medium-sized screwdriver and sliding to the side the little molding joining clips that are located on the top and bottom. Be careful not to scratch the molding with the screwdriver. Now, carefully place the screwdriver under one part of the molding and gently pry it up. It's nearly impossible to remove the molding without bending it slightly, but the good news is that upon reinstallation, minor bends tend to remove themselves.
Gently move around the perimeter of the molding using the screwdriver to pry it up. Never take one end of the molding and pull on it, as this can bend it beyond recovery. Just carefully inch the screwdriver around the molding being very careful not to bend it significantly. It you need any encouragement on having patience, just keep in mind that these two pieces are about $75 each to replace if you damage them. The rear window and side window pieces are even more expensive to replace, so the key word here is patience. If your trim is fading or damaged already, then this would be an opportune time to replace it.
After you have removed all of the molding from your car, I recommend hanging it from the ceiling. Replacing the windshield or glass is not a one day task, and you don't want this very fragile molding just sitting around where things will pile on it, or your cat will play with. Make sure that it is tucked away in a very safe spot.
Now, the process of removing the glass can begin. Take a razor blade or an Xacto knife, and begin cutting through the seal where it mounts to the car. The point is to cut away the part of the seal that is holding the glass onto the frame of the car. You want to cut down the distinct groove in the middle of the seal that normally holds on the window trim. Don't worry about hitting anything underneath, as there isn't anything under the seal to worry about with the exception of the rear window. Make sure that you cut deeply through the seal, as it won't separate from the car if it's not completely separated.
The process of cutting the seal takes a bit of patience, and there is a tendency to want to rush the job. However, you should make sure that you proceed carefully, as the old windshields are often very brittle and break much more easily than new ones. When you get to a point where the seal starts to separate completely and you can grab it with your hands, you can usually tear the seal out of the groove after scoring it with the knife. Gently pull on the seal, and it should rip itself and tear away from the car. Refer to the second photo in this project for more details.
The rear window may contain the defroster mechanism embedded into the glass. It's a wise idea to be more careful about cutting into the seal, because there are wires actually running through the seal. However, these wires in most cases don't run though the area that you are cutting. To be on the safe side, try to score the seal without cutting all the way through, and then tear it by pulling on an end that is loose (similar to the second photo in this project). This should help you remove the glass without damaging the wires.
After the seal has been cut in half, there should be nothing really holding in the windshield. Try wiggling it to see if it's loose. There is a chance that the rubber on the seal may be sticking to the windshield, in which case, you may have to apply slight pressure using your hands (no tools!) on the inside of the windshield. If the seal is significantly stuck on the inside, use a plastic putty scraper to separate the seal from the glass on the inside. Don't worry about the glass falling out or sliding: gravity will keep it in its original spot.
When the windshield is finally loose, you can rock it up on its bottom and remove it from the car. Depending upon how long your arms are, you might want to have an assistant help you. It's not heavy, but it's not too light either. Make sure that you store your windshield in a very safe spot where it won't get damaged or stepped on.
The removal process for the side glass is very similar. On 911s with the pop-out rear side widows, you can simply unbolt the entire glass, and then worry about the seal without the concern of breaking the glass. On 911s without the pop-out rear side windows, the removal process is almost exactly the same as the windshield. Be very careful not to use any tools to pry the window out.
For the rear, the process is a made a bit trickier by the addition of the defroster. After you cut and remove the inside part of the seal, you should be able to see the electrical connections that are attached to the glass. It's very important to remove these connections before you remove the glass, as they can bend and break if don't. Simply unplug the wires from the glass. There should be four total. With the plugs disconnected, the rear glass should be able to be removed just like the front windshield.
If by some chance you do break your windshield, replacements are somewhat common, and easy to find. Most windshield shops will come and install a new windshield in your car for about $150 (here in Southern California). Other locations may charge a bit more, but the general price range shouldn't vary too much from this figure.
The window trim has a small hook that fits nicely into the seal. When you are prying the window trim off, make sure that you don't bend the aluminum too much, or it may be unusable when you try to reinstall the windshield. To get started, slide back the middle joining piece and start prying back the aluminum trim.
After the seal is cut or scored, the part that attaches the windshield to the chassis can be torn away. Pulling on the end of the seal should make it separate from the rest of the seal. After this section of the seal has been removed, the entire piece of glass should be loose and ready for removal.