by Dennis Huston and Sara Belda
Many technicians consider sunroof installations difficult and inconvenient. But with a little practice, this job becomes easy and fun.
Before beginning, it is important to determine if a sunroof installation is possible on your customers particular vehicle. A roof rack or an overhead console may make the job impossible. The next step is to see if the vehicle will require additional parts. For example, the Chevrolet Camaro and the Pontiac Firebird require a reinforcement kit. Once these steps are complete, it is time to determine the proper sunroof for your customers vehicle. Each sunroof manufacturer provides a list of vehicles in which the sunroof may be installed, determined by the size, shape and construction of the roof.
Another important step of the preparation process is to inspect the vehicle inside and out and document any existing vehicle damage or identifying marks on the work order. Meet with your customer before the installation and point out anything you find during inspection. Have them sign the inspection document to protect yourself from blame for damage that may have existed before the installation. It is also important to recline the front seats, if possible, and protect the interior and door panels with covers.
Once the vehicle is ready, remove all jewelry, watches and belts with buckles. Also, be aware of rivets on jeans and jacket zippers that may scratch paint. Always wear safety glasses and leather gloves during the installation.
The first step of sunroof placement is to remove the dome light fuse to prevent shorting. Make sure inside sunvisors are in the forward position and assist handles, etc., are out of the way. Determine the location of the sunroof by placing the sunroof template inside the vehicle against the headliner. Line up the template, insuring it is straight and does not interfere with the visors.
Use a punch to place a dent in the roof at the center of the template to serve as a reference point. This will verify the sunroof fits inside without interfering with the visors, dome light, etc. It will also make centering the template easier, ensuring a better cut.
From the outside of the vehicle, locate the reference point made by the punch on the roof, and line it up with the center of the template. Find the center line at both the front and rear of the template. Take measurements and double check the location on the roof to make sure the template is even on all sides, centered and straight. Mark the edge of the template with a wax pencil and double check to see that it looks centered properly.
Staying about 3-4 inches inside the pencil line, cut out the mass center of metal using a panel cutter. If you are using a pneumatic tool for this step, make sure the air hose is not in contact with the paint.
Use a long-bladed knife (a serrated knife such as a bread knife works very well) to cut the outer sheet metal loose from any bracing. Push the bracing down to make the final cut easier without damaging the outer sheet metal. In some cases, it may be easier to push the bracing down by removing the headliner from the vehicle first.
Make the final cut toward the inside of the marked cut line using sheet metal shears in a counter clockwise direction. The Bosch or Fein shears work very well for sunroofs because neither extrudes a winding piece of sharp metal that could scratch the paint. With either the Bosch or Fein shears, there is no need to tape off the body and risk pulling off the paint after cutting. A jig saw will expel hot metal pieces that may stick to the paint and clear coat or get caught in body seams and cause rust to form on the finish of the vehicle.
Use tin snips to trim back any braces in the opening area an additional inch so they will not interfere with the inner sunroof frame during installation. Place a padded metal plate or rubber mudguard between the brace and the roof during trimming to prevent outside damage to the roof.
The first step of installation is to test fit the sunroof frame in the opening of the roof and trim any additional metal as required. If the sunroof frame is extruded aluminum, it probably has a welded seam that is normally on the right hand side of the outer frame. Always test fit the frame into the opening with the seam side going in last, otherwise the seam might get hung up on the edge of the opening, making for a tighter fit. When tightening the fasteners, always work from the center out and tighten the corners last to prevent distortion of the roof.
Extend dome light wires and relocate the light if necessary. Make sure the wires and connectors do not rattle after completion and that they are properly connected. You may also have to ground the dome light base to ensure the map light works properly. If the light is molded into the headliner, you will have to replace the light, but never eliminate it.
Refer to the sunroof manufacturers instructions for additional details related to the specific sunroof installation. There are more than 100 different types and styles of sunroofs, most with different or unique installation instructions. If you use silicone caulk as your sealant between the sunroof frame and the roof of the vehicle, be sure it is non-corrosive to avoid promoting rust in the roof of the vehicle.
Place the sealant on the roof next to the cut opening instead of on the sunroof frame. You can use the sealant as a guide when putting the outer frame into the opening. If the frame covers the sealant on the roof, you will know there is enough overlap between the frame and the metal. Remove any excess sealant from the roof and clean the glass thoroughly. In the case of tucked headliner installations, place contact adhesive on the headliner and sunroof frame. This will aid in the installation of the sunroof trim.
Watch where you set tools down and never set anything on the vehicles finish. Whenever possible, make customer contact and explain how the sunroof operates as well as proper maintenance of the roof.
Dennis Huston is the technical school administrator for the Performance Achievement Group. Sara Belda is a technical writer for PAG.
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