911 (964) Sunroof cable replacement

[nine11speedster]

Hi everyone, I have just finished replacing the Porsche 911 (964) sunroof cables. There are a few posts written on this topic but it seems I have to piece 2 or 3 threads together to get my project done. So I will try to write a more comprehensive one for the next person who need to do this job.

*Assuming your sunroof is not working, assuming your roof is stuck in the closed position

If you are not doing this urgently, I suggest you start to remove the roof before you order any parts. It will take longer but you can decide what you need.

1. Unzip the rear headliner (you will see it as you sit in the backseat looking directly above). (Pic 1)
2. Once the zipper is opened, you will see two panels held by three Philips screws. Unscrew them to remove the panels. (Pic 2) Once the panels are removed, you will be able to access the “gearbox” and the motor
3. Motor is on the left, gearbox on the right. Gear box is held by 2 Philips screws, undo them and the gearbox can be detached. There is a black round attachment that is made of rubber, it connects the gearbox to the motor, you can detach them just by unplugging it. Remove the gearbox and set it aside. (Pic 3)
4. The removal of the gearbox allows you to manually slide the roof back. The objective is to move the roof far back enough so you can access the headliner tabs, it will require about ½” of opening, just enough to get your fingers to unsnap them. To slide it back, push the rear of the roof down while you try to pull the roof back from the interior. Obviously, this is much easier with 2 persons. If you are alone, you need to try to do this from the outside, pushing down the rear while trying to slide it back.
5. Once you get a little opening, you can pull the sunroof headliner down. Directly downward, there are seven tabs to pull. (Pic 3a)
6. Move the headliner back, as far as you can, you can now see the exposed sunroof (Pic 6)
7. You can see the sunroof is held on by 4 bolts (each side). 2 are 7mm and 2 are 8mm. undo the front 7mm bolts. Undo the rear 8mm bolts. (Pic 7)
8. There is a metal spring that is holding a rod near the rear 8mm bolts. All you need to do is to move the spring away from the rod. Once this is done on both sides, you can now carefully remove the sunroof (from the outside). (Pic 4)
9. You can see the wind deflector assembly, the sunroof guide and the cables. All are held by Philips screws. First unscrew the 2 screws to release the deflector arm. Once both sides are unscrewed, you can access and unscrew the 4 screws that holds the deflector assembly. (Pic 5)
10. Once these are unscrewed and removed, you can now remove the sunroof guide. The cable and the guide should slide out – use a pull the lift motion to get them out (as there are nothing more holding it in place). You may find a white stick thing that is the guide that goes to the back, if this came out, its fine, you can position it back later.
11. Now that the guide is out, you can slide out the cables and inspect them.
12. To reinstall everything – it's the reverse of the above procedures.


Important notes if you need to replace the cables
1. All the new cables that you can purchase now – will NOT fit the existing guide. Modifications are necessary – best is using a dremel and grind the slider head (on the cable) to make it fit into the guide. There is no magic trick to this, you just need to be patient and do it with a small increment at a time.
2. When you are reinstalling – be sure you put the sunroof headliner piece back into the sliding guide slot.
3. Be sure you remove ALL the felt in the new cable. My mistake was not removing them and the motor was not able to pull the sunroof. I had to disassemble everything and do it all over. To remove the felt, the best and most effective way is to use an exacto knife, cut into the felt and peel it back following the spiral. If you are lucky, it will come out in one whole piece. If you are not lucky, this will take time to remove – I was lucky on just one of the cable, the right side was a painful and slow process – took me a whole hour just to get them off. (Pic 8)
4. Many posts recommend against lubrication. But I put in some red grease just to help out the operation.
5. Alignment – once you put everything back, just before you reattach the gearbox; stop. Now, using manual force, make sure the roof is straight. Take a measuring tape and check the distance between the opening and the edge to ensure the roof is straight. If its crooked you will not be able to open or close it, get it as straight as possible before you install the gearbox back in place. (Pic 9a, 9b)
6. Check the operation before you pop the sunroof headliner back, if it opens and closes smoothly, go ahead and pop the headliner back onto the sunroof.

[nine11speedster]

[tj90]

Very good writeup thank you! I have been resolving my sunroof issues and it turned out to be my toggle switch that needed de-carbonizing. I was only getting 7V to the motor! Since everything is apart, I was thinking of regreasing the cables, but no I am thinking of just buttoning everything back up based on your comment that soem recommend not greasing it up at all.

[Hendog]

I am in the process of replacing the passenger side cable. I too discovered the new cable head would not fit into the guide and so I ground it down to where it fits now. However the cable itself, with the added felt, produces to much drag in the guide causing the clutch to slip (as it should).

So I searched the forums for a solution and am happy to find this well documented write up. I will continue today with the removal of the felt and see how it goes. Thank you nine11speedster for your post.

[Hendog]

At first I began to unravel the felt from the "motor end"; where it stuffs into the tube and meets up with the motor gear. That was not going well. I noticed nine11 started from the slider head end. I switched to removing the felt from there and it went much better. There were a few spots along the way where the felt stayed in the coil while the string continued to pull out. It took a little while to clean out those spots. The cable ran along and through the guide and gear much better after that.

I can't help but wonder why Porsche manufactures the cable with the felt in there?

Anyhow, my roof opens and closes as it should now

[jgurnari]

know this is an old thread but I have a question...why is the rear corner not coming up completely...it is slightly low, and not coming up high enough to seal flush.

I did replace all slider hardware.

one thing that changed... the rear side corner that is not coming up totally, is the side that I had to put on a new serrated nut (pic) on the bracket...it was missing...that was the original problem and why I had to take it apart. Does that nut position, on the bolt, have anything to do with the height of the sunroof...is it an adjustment point?

I know that the front brackets have adjustments. Could it be I didnt mesure the distance prior to attaching the cable brackets as yoju did in picture #9a & 9b...I didn't do that cause I thought the roof could only fit one way and not be uneven due to the holes lining up. I made sure the sliders were at their max against where they meet the hump to push the air deflector arm.

[proporsche]

jgurnani..yes the picture shows you where to adjust the back ..loose the bolt with the alu. bracket and lift a little.Start with 2 teeth up.

Ivan

[PopsRacer]

just to chime in… (advice is worth what you paid) - dont grease the cables. I’ve seen where that leads, and it’s not good.
+1 - pull the felt out from the slider end. I used a dental pick, you use whatever makes you happy.
The slider needs to have about .0125” of material taken off of the top & the same on the bottom in order to fit in the channel nicely. (if you want to do it evenly)

[jgurnari]

done all that. just have the lower rear corner to bring up slightly. how???

[jgurnari]

saw the issue immediately!!! the nut was too far down the bracket.. slid it up and sunroof closes completely!