Now let's get one thing straight first - sunroofs aren't just for egomaniacs! If you've ever owned a car with a sunroof - no matter what type - you can appreciate the pleasant, relaxing environment that they create. They're very therapeutic. They give a much airier feeling inside the cabin, allow the release of hot air and the passing of airflow through the cabin and - most noticeably - the sun can beat down on your head, giving you that windswept feeling. The resale value of your car goes up too. And once you get used to a car with a 'roof, it's damn hard to go back to one with just an expanse of metal fixed across the top. In fact, it's been suggested that two out of every three people who have owned a car with a sunroof will have one installed in their later vehicles.
There are a few of different types of sunroofs available too...
Tilt 'n' Slide
The most common sunroof - as factory fitted to the more up-market cars - is the tilt and slide type. There are two variations on this particular design as well - they come in a choice of either a steel or glass roof. Both are configured so that you can raise the rear edge of the roof to allow heated air to vent out of the cabin, or you can retract the whole sunroof assembly back into (or over) the rear section of the car's roof to get the full open-top feeling. The glass roof version is essentially the same as the metal one - you can have the rear edge raised or the whole roof slid back for open-top motoring. But you can also slide the interior trim panel back so there's light getting in through the glass - but no air. One real advantage of this is that on dark and rainy days, you can slide the interior trim panel back to let light in - and your head won't get wet at the same time!
Pop Up/Tiltable Glass
The most basic sunroof is the pop up or tiltable glass design, which have been around for donkey's years. They let light in at all times (which can be annoying on a hot sunny day when your head's getting burnt), and are able to be adjusted so that the rear edge is cracked open. They're not great for allowing maximum airflow through the cabin whilst moving, but they can let heat out of a parked car when it's in the open position. Alternatively, it is possible to remove the glass panel altogether when you want to go all-out. But the real beauty is that nothing can really go wrong with their operation and that they are a breeze to fit. This is the one sunroof most people can tackle fitting at home - all you need are some basic metal cutting tools and the right sealers. Just make sure you measure twice and cut once...
Folding sunroofs (often called rag-top sliders) are identifiable by their fabric or vinyl top cover which slides open like an accordion. This top cover usually comes in contact with the vehicle roof to form a watertight seal, rather than using a gasket like other sunroof types. Like a steel sunroof, the folding sunroof can only be set in a closed or open-to-the-elements position (ie there is no glass roof to let the light in on its own). However, one main feature of the folding sunroof is that its aperture is usually greater than any other type of sunroof - which can mean more fun!
Tilt 'n' Slide Sunroof Installation...
To find out how a tilt'n'slide sunroof is installed, we went along to Adelaide's Sunroof City to see them put a Hollandia TVS into a brand new Mitsubishi Verada. The process takes about two days - and here's why!
The first step is to remove the factory hood lining and to install flexible water drain tubes (of a fairly large diameter) into the car's pillar frames. These tubes are used to channel the water that gets caught by the sunroof down to the factory water drainage locations at the bottom of the sill panels.
In some cars, it may be necessary to remove a structural component of the roof's frame - these can be found running either fore aft or from side to side. Any foam or sound deadening material that the factory has fitted between the roof and the hood lining is also removed to make space for the sunroof.
On the outside, the template for the relevant sunroof is measured out and marked onto the paint. Sunroof City chose to use masking tape to do this - which also served to protect the paint from some of the process that were to follow... By far, the most brutal part of a sunroof install is the use of an air chisel to cut a V shape into the roof. This V is then folded over to give enough room to get an electric nibbler in, which is used to carefully cut around the template. Obviously, extreme care must be taken in this step!
The sunroof assembly (called the "cassette") is offered up to the opening in the roof and stuck to it using adhesive - with jacks being used to support the assembly from underneath.
However, more solid mounting for the sunroof comes from a metal bracket that is riveted to the roof frame at both sides of the car.
After the adhesive on the cassette assembly has had time to dry, any sharp edges around the hole that were created by the electric nibbler are then removed using an electric file.
Still on top of the roof, the exposed bare metal that has been created by the large sunroof incision must be coated with a primer sealer to prevent corrosion.
The wiring harness for the 'roof (normally 12V supply, earth and ignition power) is then soldered into place, and the drainage tubes that have been routed through the pillars are connected to the facilities in the base of the sunroof.
The factory head lining that was removed in the beginning is cut to accept the shape of the new sunroof, and is then covered in fabric matching that used later on for the interior blind.
With the glue dried, the new hood lining is tek-screwed to the roof frame and all of the factory trim pieces (such as sun visors) are re-installed. Incidentally, the underside of the Hollandia sunroof is trimmed in foam to give the new head lining a soft feel.
The electric switch for the sunroof is simply pushed through a cut in the hood lining into a mounting hole that comes cast into the front of the sunroof cassette. If desired, this switch can be remote mounted somewhere on the dash using extension wires.
Here's what it looks from the inside with all this completed...
The next trimming task is to make up the interior trim blind. Hollandia supply a metal sheet as a base, which the installer has to trim with fabric to match that used on the new hood lining. Once this has been cut out and glued on, the supplied plastic handles then clip into the metal base to give it the finishing touch.
The trimmed blind is inserted into the cassette assembly, which is then finally sealed up by fitting a gutter along its bottom edge. This gutter serves feeds the plastic drain tubes.
A rubber edge is then run around the sunroof cavity and cut to length at the join in the middle. This protects the edge of the metal and improves the overall appearance of the 'roof.
The retracting glass panel is then bolted to the mounting facilities in the cassette and set into the closed position. This will compress the rubber seal into its usual position, and the glass remains protected by its plastic wrapper until the next step is completed...
To properly seal the external rubber edge, a bead of silicone rubber is run underneath the top side of the rubber - with any excess wiped away as quickly as possible. That's why the plastic wrapper was left on the glass!
The last step - removing the plastic wrapper. Ah, job done.
Our example of a Hollandia TVS sunroof installed to a car such as the shown Mitsubishi Verada will cost around A$2300. A simple tilting glass sunroof will only cost around A$350 installed, while on the other hand, a top line 'roof fitted with a rolled metal edge around the hole (which requires a roof respray) might run out to around A$2900 (depending on paint costs). And in case you are wondering, a rolled metal edge is a personal taste thing only - it has no real-world advantage.
In the case of all sunroofs, its condition and operation depends on its cleanliness and maintenance. However, here are the main two areas that can cause some trouble if not properly tended to...
Two of the main causes of a leaking tilt-style sunroof are age and sun damage - the seals deteriorate, leading to small gaps through which water can gush. To prevent it from wearing out prematurely, clean this seal at least twice a year with a clean, damp cloth. However, if you've just bought a car that already leaks due to a worn seal, it may be possible to source a new seal from the manufacturer.
In a power sunroof, most leaks occur because debris builds up in the trough, clogging the drain holes and therefore preventing drainage through the tubes. To stop this from happening, simply clean the trough of any dirt and wipe it with a damp cloth. Next, examine the drain holes to verify they are clear of any obstruction that may prevent water from draining. In some cases, the drain tubes may be clogged and require a flush out - which is best performed by a sunroof specialist.
Tilt'n'slide type sunroofs have a cable drive system into which dirt, grit, salt and debris can ingress - causing sluggish operation and accelerated component wear. A simple solution is to regularly inspect the tracks and remove any debris or dirt, followed by a gentle wipe with a clean cloth. In the case of rag top sliders, always keep the vehicle roof clean and waxed. Most manufacturers recommend mild detergent and occasional application of good quality all weather vinyl dressing. Note that in the case of any motor driven sunroof, follow the manufacturers' instructions for lubricating the tracks and drive system - and it is highly recommended that the sunroof gets serviced at regular intervals by a professional.
Now get out there and pop your top!
Sunroof City +61 8 8211 7600