It appears that there is very little detailed information on this subject, so I will attempt to share what I have learned. I have taken several pictures to illustrate every step - so hopefully it will create a more comprehensive and easier way to perform this simple job, which somehow has, in the past, mistakenly been surrounded with an aura of difficulty.

I will start with the assembly process, so this time, disassembly is in reverse of assembly! I have also omitted how to re-install new sunroof cables, and how to reinstall the weatherstrips. I believe those are easy, and will be covered later.

Warning: do not use contact cement to glue the weatherstrip. The strong solvents have the tendency to melt fresh paint in the sunroof opening edge. The other negative is that it must be applied liberally to work well, so it is messy. Probably a better way is to use a small dose of super gel and work small areas at a time. Others can chime in with recommendations. The idea here is to build a nice FAQ.

If you replaced the weatherstrips wait 24 hours for the adhesive to cure, before trying to insert the sunroof panel. No special tools are needed for this job, allow 4 hours the first time.

The first step is to identify the left/right main rails. Here is a picture of both rails as viewed from top. The rail on the top of the picture is the left rail. The front on the rails is on the right side of the picture. Rails are shown with cables already inserted.

Stage both rails side by side and make sure that they look like this:



Notice the anchors on the back of the rails and the proper position facing up (these anchors are attached to one end of the cable and their job is to pull/push the sunroof panel):

Notice on this picture how the cable on the left rail is inside the inboard groove. The cable on the right rail goes on the outboard groove.



Here is a picture of the two grooves inside the main rails:


IMPORTANT: the rectangular groove in the inboard side of each rail is where the sunroof headliner rides.

The next step is to insert one of the rails with the cable already in it, inside the sunroof cavity. Let the rest of the cable just hang out in front of the car. If you wish you can lay a towel to protect the paint. There is a long strip aluminum retainer that has is inserted in front of the rails. Three screws hold this retainer and the rail in place. See figures below:

Left rail showing the cable coming out in the inboard groove



Left rail shown with center aluminum retainer in place. Anchoring brackets are pulled against the stop in this picture



The next step is very IMPORTANT.

Insert the second rail AND the sunroof headliner inside the rectangular grooves. This the only time where this operation can be easily performed.

Headliner nicely in place, notice the cables are still exposed in the front. Also how both cables are inserted in the opposite rail.



You can now slide the headliner inside towards the back to provide access for the next steps. Don't worry, it will not get lost.

The next step is to complete covering the cables with the corner brackets and the three front brackets. Make sure that there is a mylar type of material glued to the bottom surface on the car, this is where the two cables ride. If the anchoring brackets on the back of the cables move, do not worry they can be repositioned later. Following pictures show the assembly steps, including is a cool air dam available only as an option.







Ok, you may doubt and ask why the headliner has to go first?

Here are some pictures of a late futile attempt:

NO, NOT THIS WAY



NO, NOT THIS WAY - DO NOT BRUTE FORCE IT THIS WAY EITHER:



So remember the headliner goes together with the second rail!

The next step is to prepare the sunroof panel for insertion. Turn it upside down. Remove one screw from the front guides so you can pivot them inward and out of the way. The back brackets have also a long metal tab that can be pivoted inwards:



The next picture illustrates how the sunroof cable anchors are attached to the sunroof panel. You will do that later once the sunroof panel is in place in the roof opening.



Notice in the picture above how the cables are connected to the sunroof panel with two screws. There is a small metal tab that below the screws. This will be done once the sunroof panel is inside the car. Picture is for illustration only.

Now you are ready to insert the sunroof panel in the roof opening. Back end first. Take great care on this step, to avoid scratching the sunroof panel or the front of the roof. It should go in easily and fit snugly in the opening.



Notice how the back of the sunroof panel is below the roof line, that's ok.

Temporarily, insert the sunroof crank to move the cables anchors to line up with attaching location in the sunroof
panel:



Slide the retainer between the two tabs. You may want to use a flashlight to make sure that they are inserted properly.



Fasten the two screws and swing the sheet metal lever around and below the pin. This is the part that moves the sunroof up in the back. Brilliant design!



Move now the front and swing the front guides. Do not tighten the two screws yet. Just finger tighten them at this point.



Rotate the crank SLOWLY while observing outside the car, just in case. The sunroof should retract and clear the roof and come forward nicely. The last stroke should push the back of the sunroof up.

Stop if you feel any resistance.

Repeat the above steps a couple times - this allows the front guides to find their "natural" place and align themselves. Tighten the front guides now.



Slide the sunroof headliner forward now and clip the front to the sunroof panel. Take care of lining up the clips with the holes, before pushing them in. Observe each one going in to avoid messing up the cardboard around them.



Reposition the crank now so it is in the right place in the closed position. Clean your fingerprints.



That's it - enjoy your sunroof!


_________________
72 tii A4, 72 tii Alpina, 98 M3 coupe

Don't argue with anyone that will not consider the possibility of being wrong...

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