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Take a deep breath and brace yourself: every single year of Fox Body Mustang qualifies as a "classic car", so long as you are going by the standard rule of being over 25 years of age. That's right, that pristine 1993 Cobra is in the same classification as a 1979 Indy Pace Car. Now, in many ways, that's not a bad thing. The Fox chassis has held up well over the years, there's a ton of aftermarket support, and they might be the most malleable Ford performance car made since the 1932 Model 18...you know, the Deuce Coupe. Whether you like them as a drag car, a road course racer, a rally car (we've seen 'em!) or just a nice driver, the small size and big potential of the Fox-chassis Mustang has earned its place in automotive history, carved into stone. And they are still approachable in value, so if you were thinking about a potential project car or a mild restoration project, you would be hard-pressed to do better. There's just one issue with these cars...for every clean, cared-for example that was loved from day one, there's about a hundred that have seen every sort of use and abuse known to man. This is where the "classic" part of the equation does not work in the average buyer's favor. Even if the car wasn't beat to within an inch of its life, age takes its toll and one of the biggest tells on 1987-1993 Mustangs is the quarter windows. The car overall can be okay, but chances are good that if you check out the black surround that was new for the 1987 model year, you'll see checking, heat damage, shrinking, lifting and other undesirable traits.
If the photos don't tell you what you need to know about the 1989 Mustang LX that we have on-hand, let us explain: this poor four-cylinder hatch has seen seven shades of hell within its lifetime. In fact, its only saving grace is that the chassis is in great condition. It's as rough of a car as you'll find, an absolute basket case we picked up for a couple hundred dollars. Our plan was to shove in the nearest 302, get it running and road-legal, and proceed to drive the wheels off of it (again). Most people would write this car off as a parts-only car, but we had a pile of parts laying around from a different Mustang build and a spare 302 on an engine, so we chose to resurrect this car after all. It'll never be a restored beauty but we do want it to be a solid performer, and we discovered early on that one item that badly needed to be addressed was the quarter windows. While the glass itself was fine, the seals were not. They were so cooked that the rear corners were lifting away from the body and there was a spot on the passenger side that had deteriorated so badly that water was actually leaking into the car. That had to be fixed and with the interior stripped out for other work, it was the perfect time to address the situation once and for all. With a set of Drake Muscle Cars quarter windows for the 1987-1993 Ford Mustang (part number E7ZZ-6129710-1B) and a quarter window installation kit from Late Model Restoration (part number HDW-29710B), we took on the project in our driveway. Follow along as we show you how we completed this in just a couple of hours!
In these photos, you can see just how bad our hatchback's quarter windows were. The outer seal had cooked in the sun for what looked like years and were actually crumbling away at the top, where it was allowing water to leak into the car (you can see the outline of where we put foil tape over the section in question to help keep the water outside of the car).
To get started with this job, a lot of the interior has to come out. We've already been at work getting everything out of this car, but to get access to the back of the windows, you will need to remove the back seats, the trim panel at the rear of the headliner, the front seatbelts at the shoulder mount point (these use a T-50 Torx bit), the rear speakers and grilles, the taillight/hatch panels, and the big panel that runs from midway into the hatch to the doors. To remove that large panel, you will need to loosen the headliner trim on the sides and loosen the door sill plates. Once those are out of the way, remove the jute padding to expose the nine mounting points of the quarter window.
Next, remove the roof rail molding by removing one screw on the A-pillar, near the rear-view mirror, then pull it away from the body gently. Once you've done that, it's time to start removing the quarter window itself. The quarter windows are mounted with nine 3/8" nuts to the body. Seven are pretty visible. The eighth and ninth locations (yellow circles) are well hidden in the body structure. Be sure you find and remove them...otherwise, you'll have a bad time. Just like we did removing the driver's side, when we missed that final nut at the far rear point. Learn from our mistake.
Now this is the point where you need to be very patient and careful. The quarter windows are sealed to the body with butyl tape, a tar-like substance that can be anywhere from gooey to cement-like. However you choose to approach this, BE CAREFUL. Our method was to use a plastic prying tool along the edge of the outer trim where it meets the door frame while applying light pressure inside on the glass to start the process. Once we were able to get the glass to start separating, we used the tool to "cut" through the butyl until it finally separated from the body.
Now that the glass has been pulled away, you can see just what thirty-odd years of life can look like underneath the area between the glass and the outer quarter window trim. On pre-1987 Fox Mustangs, this would have been filled with a sail panel that had a louvered appearance to it. With the 1987 refresh, this area is covered by the extension that provides a smoother appearance...but that leaves a gap where dirt, dust, or dead ladybird beetles can collect.
While your quarter windows are out, take the time to clean up the area! You will have to remove all of the remaining butyl tape from the surface. We got lucky and were able to "ball" it up using our thumb and a rolling motion, but be careful, there might be some sharp points underneath that mess. We then washed the dirt and crud (and dead bugs) out with soap and water. In our LX's case, we worked on the dent underneath the driver's side window and touched up some of the areas around the edges where the sand had worn through the paint. Luckily, we had some mixed up Cabernet Red on-hand for just such an occasion!
To prepare the installation, we started by laying the butyl tape that came in the Late Model Restoration kit onto the window surface. Unroll it slowly and gently press it onto the surface, just outside of the glass. If your quarter windows came out intact, use them as a guide. We went around the glass perimeter, then took strips and formed a "donut" around the mounting studs, nothing too thick, just enough to fill the gap between the strips.
Now, this next part is crucial, and you might want to ask a friend for help. GENTLY set the glass into position and start threading on the holding nuts. Once you have all nine nuts on their threads, HAND-TIGHTEN them down carefully, working your way around the perimeter of the glass, then towards the back. Tighten them down in small increments, and do not over-tighten! You should be able to see the butyl tape start to compress as you progress.
Once you have the quarter window set in place, you can re-install the roof rail trim. This little protrusion on the quarter window slips into the roof rail trim's channel (outboard). Just be careful to not break that protrusion off!
And the end results speak for themselves. The entire process, including the removal of the interior, should only take about half a day if you don't need to do any work between removal and installation or any other mitigating factors. The fit is great and we're happy to be able to park the car outside without worrying about whether we're going to see a puddle of rain water in the floorboards or not!
