Fixing the Sunroof
- joepampel
- Apr 1
- 20 min read
Updated: Sep 8
Harkening back to my consulting days, here's the answer first and if you want the saga, well it's still all there.
The Sunroof was jamming due to some poor prior repairs including greased cables that were now full of hardened gunk. I needed to replace the cables also partly because the section by the drive gear had worn down (or stretched?). Somehow narrower at any rate.
The driver's side rear drain was clogged, which had caused rust in the tube, and that required a replacement tube. I tried and tried to clean it out to no avail.
The transmission wore out due to all of the abuse (high friction) Found a used one on eBay that works great for $90. (new? $675)
I re-glued the loose parts of the headliner and anything else that might interfere with the roof panel.
While the thing was all apart, I removed the old seals, cleaned off all the old glue mess and installed new seals.
Now it slides open and closed like a champ. It's been the most expensive single repair the car has needed thus far.
*******
Early on after buying the 911, the sunroof jammed as I tried to close it. A quick web seach later I dug into the toolkit to find the manual crank, cranked it closed and found a dead fuse. I didn't think too much about the "why" of it all. Oops.
A month or two later it started to not close all the way, the rear would not rise up. So I would give it a gentle lift with my hand as it closed. That lasted about a year. Then one day it just stopped moving altogether.
When the sunroof finally jammed shut, I had to figure out a) how to get it apart and b) how to fix it. I really wasn't ready for what I found.
There are a few pieces to this I suppose:
The early style sunroof cables are NLA, so owners need to fit the 964 style. These have felt wound into them which can make them a bit of a tight fit, so the felt usually has to come off first - if you have older guides.
You are not supposed to grease the sunroof cables, or this is the CW of the resources I have read on the net. Perhaps counter intuitive, but the cables and mechanisms are out in the elements and grease just collects dirt, can get tacky and gum things up. It can also liquify in the hot sun and run down on to your headliner.
Prior work in my case added more sealer in various places which made cleanup an arduous process, and there were missing parts which I am still working through (what were they, did this car come with them and where did they go)
The sunroof drains were clogged which I did not catch until later. This had caused rust in the tube at the rear, and caused some mild water damage to the headliner.
One of the cables had a small kink in it which caused it to bind in the tube and I ultimately would wind up replacing the cables.
A helpful gent on the Pelican boards identified that I have 964 cables. That was a recommended dealer fix at some point I was told. These days the 964 cables are the only available part. The person who had replaced them did not remove the felt, they greased it pretty heavily. Thanks, buddy.
Potential Parts:
Short section of sunroof seal: 911-564-193-00
Long section of sunroof seal: 911-564-191-00
Rubber seal (back of sunroof): 901-564-905-05
Long felt strip (under wind deflector): 911-564-409-00
Short felt strip (x2): 911-564-409-01
Front Sunroof Guide(x2: 911-564-045-00
Sunroof guide lock plate(x2): 911-564-451-00
Front plastic guide clip(x2): 911-564-433-00
Rear Plastic guide shoe(x2): 901-564-431-06
Wind Deflector Hinge (kickstand): 911-564-127-00
Male Pin for sunroof motor connector: N-017-564-1
The manuals and the Pelican Parts site have some good procedures and photos of what is going on inside the roof assembly, but I still had a hard time visualizing it all, and as I mentioned, I am missing parts (I think). So I am writing this. (links to resources below)
Step 1 is removing the headliner which is clipped into the sunroof. Mine was stuck so first I went up into the roof to try manually moving it. This means unzipping the headliner, and unscrewing the longer of the two trim pieces that cover the sunroof mechanism. Then you can remove the screw in the transmission to use the manual crank to move the cables.
Pro Tip: As it happened, I had a rip in my drivers seat so I pulled it out to go to the auto leather specialist. Having the driver's seat out made working on the sunroof much easier. If you're tall I would defintely consider removing it. Otherwise, moving the driver's seat all the way forward so you can lean back in the back seat works ok. YMMV
Once the panels are out you can see the motor and gearbox. They are connected by a rubber "clutch". There is actually some slip built into the gearbox too; there is no electrical "stop" in the system to turn the motor off so over-run in either direction needs to be accomodated and it is also (afaik) for safety, to avoid pinched fingers etc.
I used a trim tool to get up between the headliner and sunroof panel since I could not move the sunroof at all, even manually with the crank. When you are not trying to manually move the roof, always sure that the screw on the gearbox is in snugly. It is what enables the motor and gearbox to engage properly so if it is out or loose you will have issues. It may sound obvious or dumb perhaps, but it can happen in the middle of a job. (ask me how I know...)
Trim tools are really handy. This one is great for all kinds of hidden clips as seen on doors, bumper trim, etc. The angle made it a good solution here. I found one spot that was loose enough to pop out and then just moved across from there. There are only clips on the leading edge.
Step 2: once the headliner is loose you can slide it back into the roof and out of the way. It rides in a slot that is part of the sunroof tracks. Sliding it back will expose the sunroof guide bolts (8mm) and the cable guide bolts. (pic above). The front guide is a metal bracket that is an offset "Y" shape, and inside the Y is plastic so it can slide. There is a plastic sleeve over the end of it. The captive nuts below it rotate (above it really) and set the resting height of the front of the sunroof. The guide is sitting on a ceiling panel here and you can see how those clips work.
The guide with the plastic sleeve (above). It also seems to have grease in it.
The plastic collars around the guide mount "captive nuts" rotate to move the roof panel up and down so it closes nice and evenly. Easy to adjust as needed when you put it back together. I wound up needing mine all the way tight to get the panel even. I am guessing that this is because I replaced the missing felt that sits under the wind deflector.
Next, rotate this sping loaded clip out of the way so you can remove the cable guide. It has two pieces, a flat metal bit that supports it and then the actual guide piece that connects to the part that slides along the track. Once the guides and cable ends are unbolted, the panel can come out. (2x7MM bolts)
Put some towels out to protect your paint and then slowly move the sunroof panel forwards, up and out of the car. It is heavier than it looks (~12lbs); not heavy, but heavier. Just use caution. It's pretty simple if you open your windows so you can reach inside.
The headliner panel is still in the car here (it rides in a track), but will have room to come out once you loosen the cable track (the long black aluminum guide). I learned during this project that these are the later cables from a 964. The earlier style cables are NLA.
Remove the guide piece that the wind deflector support connects to. (2 phillips screws) and then remove the 1 screw with small bracket at the front that holds the cable guide in place. Both of my little "kick-stands" were pretty brittle so I ordered a new pair.
Remove the screw and bracket that hold the guide in place (above) & then slide the guide forwards and out of the car to expose your cables and the cable ends. Be careful of the plastic locating pegs in the rear that sit in the guide and then fit into a hole at the back of the roof. They are important, and not sold separately. If they stay in the roof, use some long pliers to get them out.
This is a good time to look inside the roof and make sure there is no debris, old sunroof parts or whatever back there. You don't want anything to get stuck in a sunroof drain and cause rusting or water damage. Turns out I had a very small bolt in my driver's side drain.
Here is what the system looks like out of the car. I didn't tuck the tube & cables into their tracks but otherwise it's pretty close to how it sits when installed. The tube actually sits inside the guides. The white plastic pin is what helps to locate the guide in the rear of the roof section and it should get some body sealer on it before it gets reinstalled.
In true Porsche fasion, the guide rails are the same extrusion on both sides, just with different holes punched in them. The cables are different side to side, slightly different lengths and the piece at the end of the cable is different.
As I cleaned things up, I periodically checked the cables in the tubes to see how smoothly they would move.
I took the guides inside to the slop sink and scrubbed them clean with degreaser and a toothbrush.
With the guide out, you can see your cable and the "glide" it is attached to that pushes or pulls the sunroof around. You can also see how gummed up the cables are. I wound up removing the felt from mine because the grease and dirt had destroyed it. You can (hopefully) use an awl to loosen the felt at the "slide end" and then just unwrap it if you are going to remove it. Part of mine came out this way, the rest was a mess. It came off very easily from the new cables.
But first, what broke in the sunroof? The passenger side cable pulled out of its crimp to the glide. Probably because the mechanism was so stiff. I'm lucky the gearbox has a metal gear, and nothing else broke from stress. The gearbox has slip build in to protect it, and a rubber linkage (they call it a clutch) to absorb shocks.
I was able to clear the hole in the slide out with a small drill bit until I could get the cable back in and re-crimp it. I used vice grips to crimp it. Not too much or it may not slide well in the track. After looking at a number of posts on the Pelican boards, this seems to be a pretty common failure point, and a common fix. Some folks not only re-crimp the cable but also add a dab of JB Weld for good measure. New cables are about $500 a pair so fixing the old ones is certainly worth the effort.
Twisting the end back on in the direction that the stranded cable was wound in is what you want to do here. You can see the rear of the height adjustment here, you loosen the screw and move the "nut" portion up or down along the toothed surface. Make sure it can rotate freely at both points. As the rear of the roof comes up during closing, this has to pivot. (ditto, pivoting down when you open it)
The cable on the left is worse, but both were pretty greasy and crusty. I scrubbed them in the slop sink with an old toothbrush and degreaser to try and save the felt, but wound up removing it. It was too far gone.
I removed the tracks and scrubbed them out as best as I could with a brush, Zep and plenty of hot water. Be careful removing them because they can push against the headliner and those tiny nuts are a pain to get to and there are clip nuts and metal panels that are sharp.
One of the leads to the motor power plug came off so I needed to order a new pin; luckily Stoddard carries them. It's the same pin used inside the doors, for the oil cooler fan and on the power mirror harness. Not a bad idea to order 10 of them to have on hand.
The underside of the sunroof panel. (front edge towards bottom) You will probably want to replace the two plastic guides (arrows). There should be 2 felt pads in the rear corners. There are 2 similar felt pads on the sunroof trim panel in the rear corners as well. (shop manual photo below matches what I found) The longer plastic piece is a glide that pushes the wind deflector down so it is important that it is solid and properly located. If your roof is hitting the deflector, this is probably the first thing you should look at.
That rearward plastic guide is interesting. I found it installed with the slanted part facing forwards. The parts diagram shows the flat side facing back. The shop manual shows slanted side forwards. It glides on to a bump on the back of the headliner panel as the roof closes to help lift the roof panel. Mount it as shown in the pic.
The pivot (large screw in the picture) needs to be free to move. If yours is stiff, use some PBlaster and work it loose. As the panel moves into the roof it pivots flat, and when the sunroof closes the motor "screws" it up to vertical to get the rear of the panel into position. (Literally twisting the cable) You can test this by cranking it by hand. The little rod coming off of the sunroof cable glide pushes the headliner down as it closes. You can lay the sunroof panel on a moving blanket and partially re-assemble it to see how everything fits in the end.
With the mechanism out, you can remove the old fuzzy seal, and then use 3M Adhesive remover to clean up the area so you can get a nice strong bond. I used an old toothbrush to help with this. Put some rags in the guide channel in case any solvent flows towards the rear. Don't be stingy with the solvent, it can take a bit to get things loosened up. My car had black trim adhesive as well as the yellow/green stuff and it was just trowled on in places. I guess it was leaking at some point. Maybe they forgot to check the drain? Who knows. Mask off the roof; any drips or splashes will need to get cleaned of the paint with a little gentle polishing compound or a soft cloth with a little adhesive remover.
The car appears to be missing the felt under the wind deflector, so I replaced that. It may be too thick as I cannot adjust the sunroof panel below the roof level; CW says it should be a tiny bit below the roof on the front edge to minimize noise. The other felt pieces pictured get cut into strips and glued to the headliner as well as the sunroof panel.
I have circled the missing guide lock plates (45) as well as the other plastic guides you should replace while you are there (43 & 49) 43 is reversed in this picture for some reason. #49 is what pushes down the wind deflector as the sunroof closes. (via part #23)
One of the leads broke off the harness side of the motor connector (R) as I removed it. I used the connector tool to push out the remaining pin so I can replace it. Its a standard VW/Audi/Porsche connector. Stoddard carries the male pins that snap into the harness-side of the connector. If you search online you'll see the VW part for sale which includes the connector and both pins.
The sunroof panel seals had sealer glopped on as well as the original glue. It took a while to clean up. My arrows on the tape are marking where the old seal ends to help me place the new one. Probably trying to fix the "water leak" that was really "water retention".
I got the roof panel cleaned up and had a good think about which adhesive I would try out. There were some posts that favored the 3M black super trim adhesive, since the seals are black it blends in better. In the end that point won out for the panel. It gets tacky fast and is hard to brush around accurately as it is very gooey. The yellow super spray adhesive gives you more time to work and is easier to brush into place (say some posts). I used it for fixing up the headliner and it was very nice to work with honestly. I would probably use it for the seals if I had this to do over.
I think what I learned quickly about the black adhesive on my first go-round at this was:
Keep the adhesive on the lower (flat, not round) part of the seal so it stays hidden
Work quickly in sections. I marked center on the seal and center on the roof, and then worked outwards, one side at a time, a few inches at a time, level it and then tape it in place.
When you remove your painters tape, do it sideways so it does not pull on the new seal.
I did the rear rubber seal last, and I used painters tape to mark off the borders of it so I would apply the sealer to the panel accurately.
I applied sealer to both the roof panel and the seals, just a nice light coating so it doesn't ooze out all over when you push the seal down. It still made more of a mess than I would have liked.
The top of the seal should not be higher than the roofline. I used a plastic trim tool gliding over painters tape to level it off as I went. (it's still not as even as I would like)
One thing that was tricky is the new fuzzy seal for the rear of the sunroof panel was taller than the old one (or maybe they shrink over time?) so lining it up with the rooftop was trickier than I expected. I used trim tools covered in tape and riding along on tape to try and keep it all pushed down evenly and scrunched against the vertical panel it bonds to.
It took nearly 2 hours to get both cables fully cleaned up once it was clear the felt could not be saved. Pulling felt off of the new cables was the same process, pick it loose at the end and then slowly unwind it.
After (top) Before (bottom) that was a spot where the felt was not too bad. A lot of it was just mush though.
The sunroof panel after the glue dried. I just marked off the roof center and seal center and worked out from there. (there was a lot more tape on it during the work). I installed the rubber seal a mm or 2 further rearward to give the water running over the roof more room to flow down into it. I don't know if that will help or not. It seems too bunched up against the felt seal. I am asuming that is why is it s "V" shape, to channel water towards the sides where the drain holes are.
Where the guide tube goes through to the roof cavity. 8mm nut and washer hold the tube in place on that stud. The hole to the left with white body sealer is for the plastic locating pin. Use some new sealer to keep it from leaking.
What the pin looks like, and my broken wire. I stripped it and then needed to take a few strands out to make it thin enough to crimp into the new one. The automated stripper I use makes this an easy fix, even if it's over your head. (it's listed here: Amp Building - Tools & Tips)
There we are with the new pin in place.
I remounted the tube and then the motor. Leave the gearbox until last - you want to install & align the roof panel properly first and then get it all bolted down before you install the gearbox. I put it in too early and got to pop it back out. This aligns the cables so the roof closes evenly side to side and hopefully closes proplerly in the rear.
Putting the guides in: I put the long felt under the wind deflector as it has holes in it already for the mounting screws.
The middle pieces where the wind deflector supports connect should be centered where they connect to the deflector such that they go down easily. The sunroof slides up and pushes them down into a gap and that allows the deflector to move out of the way of the roof panel. You can slide the end around of the support a bit if needed. It's just held in place with a rubber 'nut' which you can slide around.
The post coming out of the sunroof cable end is there to push the headliner down as the sunroof closes, so you'll want to make sure the rubber sleeve covering it has its best coverage facing downwards to the headliner. If you had to file the ends to get 964 cables to fit earlier guides, this rubber may have gotten chewed up.
The big silver bracket on the end of the cable needs to rotate easily - it is pivoting as the roof opens and closes. The toothed sections can be used to adjust the rear height if needed.
You need to be a little bit of an octopus here since both guides go in together with the headliner panel between them in its track, and the wind deflector shares the bolts that hold down the guides, and in the rear the plastic pins need to go in their holes while the ends of the tube fit into the rails. It all works out though. Be really careful not to strip the holes in the roof. Slow and gentle.
Headliner panel and guides are in place here.
As it was when I opened it up, and in the manual (above). The sloped side rides over a hump on the sunroof panel to start raising the roof panel when closing. The final bit of lift is from the motor "drilling" the cables.
And there it is. Lots of room for improvement; the seal is a bit more uneven than I would like, but it was my first time and I'm glad I could repair the cables and get everything cleaned up so that it works fairly smoothly now when I turn it by hand.
It's still not as smooth under power as I would like; it opens a bit better than it closes. I think the vinyl is a little bunched up at the front and not sliding in the track as well as it should.
If I can't get it to fully close by itself I'll probably replace the cables, they look a little stretched (narrower in the section by the gearbox) and perhaps that is the difference?
Special thanks to the Pelican Parts forum folks who have posted a number of great threads about sunroof repairs! I also watched Joe Engineer's videos about his sunroof repair. Links below. I was pretty nervous about doing this at first, but seeing so many others dig in and write up what they dealt with really helped. Having taken it all apart 5? times now, I can do it in about 15 min now.
Epilogue
The sunroof worked “meh" for a couple of weeks but now is having trouble moving again. I detached the headliner to remove a variable but it still is having trouble moving. I disengaged the motor and used the hand crank to evaluate the cables, and it is really, really hard to move it. No wonder the motor can't do it.
Upon inspection, the cables were very rusty (white, as well as reddish-brown) which indicates a couple of things:
1 - the roof area took in water that didn't drain properly. I had not checked the drains before. DOH
2 - white rust here is going to be Aluminum Dioxide. So probably from the rails?
3 - the reddish brown rust is iron and is either the cables themselves or the tube guide in the rear? My assumpton is that the cables should be stainless steel, so it's likely the tube in back.
I spent a lot of time cleaning up the cables, again, and the tube as well. I used a vinegar solution and then an overnight soak in Evaporust combined with lots of brushing and rinsing. I used the cables to test how well I was doing. Things got smoother and smoother, but never really "good" by my unofficial gut feeling.
AND I finally I checked the sunroof drains. The drain to the rear on the driver's side was blocked. I tried getting weedwhacker line up the drain hole (starting from under the decklid). That was a no go. Next I tried some vacuum line, also a big nope. I ordered a sunroof drain cleaning brush online - you'll need 40" or better to clean these comfortably.
While I waited for the delivery, I decided to make a tool. I took a small drill bit and fit it into the end of some vacuum line. Then I taped off the sides of the bit with painters tape to minimize any scratching, but left the end exposed. I fed this contraption up the plugged drain hole and twisted it as it got to the blockage. The rubber let me build some twisting force on the bit. This was a success. I checked the other 3 drains as well, running the brush through them and also running compressed air and then water through them. The one that had been blocked was blocked near the top. There is a section of rubber tubing that goes from the rear of the roof compartment to the drain. You can get to it via the zipper opening in the headliner although there isn't much room to work and you risk damaging the headliner. While I am sure I could have gotten the tube out, I am less confident I could have gotten it back in place. I found what had been blocking the tube up inside the roof afterwards - a small bolt! It was very rusty, from some ancient repair I suppose.
I cleaned and disinfected the headliner in the meantime since it had gotten wet, leaving it out in the sun to dry. UV light is a natural disinfectant. I took the opportunity to glue down any loose sections that might interfere with the roof closing smoothly. I used the Yellow super trim adhesive, spraying it in to a small dish and then using a brush to spread it carefully. This was actually pretty neat and simple. The sprayer is well suited to this, and the adhesive will re-liquify any dried glue in the dish. I used wood furniture clamps to hold the headliner material in place while it cured. Nice and wide, and reasonably soft.
I bit the bullet & ordered new cables and a new tube. I got the new tube in place, and then prepared the cables. I first tried the cables in the guides as-is but they were pretty hard to move, and the slides on the ends did not fit. This confirmed for me that these are the original 911 guides.
I removed the felt and then got the dremel out with various small sanding/grinding attachments, followed up by some hand polishing with files and sandpaper. The new guides are about .2" tall; the old ones about about .175" tall, so to keep it even I'd want to remove about .0125" of material from the top and bottom. It's pretty easy going, just tight under the little pin that pushed down on the headliner. You can use a very thin file there. Keep checking to the if the pieces fit and how well they slide in the guide. You aren't removing a lot of material. When it slides in easily, you're done.
With this work complete I put the assembly back in the car and it turns smoothy and fairly easily. If I push back a little on the sunroof, the manual handle will spin in the gearbox. However the gearbox itself appears to be worn out; it just slips as the motor spins, and the rear of the roof won't come up, I suppose because it can't hold the tension in the cables. I found a used one on eBay for $100 and we'll see how that goes.
I intalled the eBay transmission and it all works perfectly now. That was the missing piece. The old gearbox just slipped even with the screw in as tightly as I could get it.
On the plus side I drove an hour in a very heavy rain storm getting back from an auto-x yesterday and the roof didn't leak! I take that to mean the drain works and the seal replacement job was "ok". This was a long drawn out and kind of expensive fix but it feels good to have it done. I'm kinda tall and having a sunroof I can open is table stakes.
Resources:
3M Specialty Adhesive Remover: Part# 38987
3M "Yellow" Super trim adhesive: Part# 08090
3M "Black" Super trim adhesive: Part# 08008
3M Seam Sealer: 08367 (for guide pins)
Sunroof Drain Brushes (30" or longer) - search online.
McMaster-Carr - long cleaning brushes for the tubes: https://www.mcmaster.com/products/pipe-cleaning-brushes/shank-style~handle/low-scratch-tube-brush-sets-with-handle/
Pelican Parts Tech How-To: https://www.pelicanparts.com/techarticles/101_Projects_Porsche_911/85-Sunroof/85-Sunroof.htm
Pelican Parts 911 Forum Posts: https://forums.pelicanparts.com/porsche-911-technical-forum/1174676-tech-topic-sunroof-seal-replacement.html
Joe Engineer's 3-part video about his Sunroof repair
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