Stuck sunroof cable
 

I am partway into refurbishing my sunroof and have hit a snag. the sunroof doesn't work at all (motor runs but clutch slips), and it opens manually via the trunk with great effort.

I have removed the sunroor liner and unattached the cable bracket and cable c-clip. I've also removed the crossbar. At this point the sunroof slides easily, so I don't appear to have any problems with the rails.

At this point my understanding is that I should be able to feed the cable out from the inside of the car while holding the sunroof button to the 'close' position. The motor runs and the clutch slips, but the cable does not budge.

In the trunk I have tried to turn the cable out manually but it simply will not turn in the direction that would feed the cable out of the front. It does manually turn in the direction that pulls the cable rearward.

So at this point I can't move the cable and I also cannot remove the motor because the enough of the cable is still engaged in the gearbox so that I cannot pull the tubes off.

Any suggestions on what to do next?

Suggestions
 

Two or three conditions are probably at play. At minimum you will need a new cable cause the cable is toast. Even if the motor gear teeth are stripped the cable winding will be shot

1) The cable winding on the cable is stripped so the gears can't grab it.
2) If the winding is chewed up much at all it won't feed up through the cable tube to pull it out from inside the car.
3) Sunroof motor gears are stripped & or the clutch drive is stripped.

Bottom line you will probably have to cut the cable.

Going forward remember to not force pull the cable too hard or you bend the tube and it all must be replaced...

Eventually you will have to open up the sunroof motor to get at the frayed cable. And Eventually you will need to cut off one section (end) of the cable so it will cleanly pass through the tube. Choice is while it is in the car or out of the car.

Cutting the cable must be precise & clean. Wire or cable cutters probably will leave a burr or tail of some sort that won't pass the tube. I used a dremel with a very fine steel cutting blade. You could use a similar blade on a drill.

So here is your fix...Get your cutting rig hooked up and go the the cab of the car. Cut the sunroof cable mount flange/connector off of the cable. I repeat be very precise...go slow. Now that you have a clean cable end go the the trunk and unbolt the motor from the trunk mount. Unclipp the retaining clip holding the tube to it so the motor is somewhat free of the tube. Now while you are trying to hold the tube so it won't kink at an upper bend, have someone grab the motor and start pulling the cable out of the car to the rear.

Or you could cut the cable rear of the tube via opening the motor up while inside the trunk by removing the nut on the emergency crank spindle to find a clean upper section of cable ....but there is a lot more room in the cab.

Reinstall is simple. Once the assemblies are back in place feed in the cable from the interior of the car...and you already know the rest

I forgot to mention this is a 1985 300D

I have unbolted the sunroof motor from the car body and then opened the motor to remove the cable from the gear housing. The motor is now completely out of the car.

After getting it out of the sunroof motor I found the cable to be stuck in the rear section of the tubing, i.e. the smaller piece of tubing that is at the very rear of the cable. I expected that this should slide off once free of the motor housing, but it would not budge. I eventually started cutting off sections of the tubing using a pipe cutter and eventually found a small section of the tubing where it looks like the cable teeth are almost 'welded' to the inside of the tubing. I finally had to cut the cable in front of this section of tubing that would not come off.

At this point I had all of the rear tubing in trunk removed and the motor out of the way. i went to the cab of the car and started to pull the cable out towards the front of the car. At first the cable pulled out smoothly, but after a foot or so it simply stopped and I couldn't get it to budge. It would easily slide back and forth to a point, but then stop.

So using the pipe cutter I cut the flange off the very front of the cable in cab, then went to the trunk and started pulling the cable toward the rear. Again it pulled out smoothly to a point then stopped. However this time I can't get the cable to move back in the opposite direction, it's completely stuck.

In retrospect I wasn't thinking clearly when I started pulling the cable out the rear because the front of the cable, i.e. the portion that runs along length of the sunroof, is not cable at all but rather a solid metal tube that is not flexible like the cable. Of course as that solid section moved backwards it was going to jam as soon as it got to a curve in the sunroof tunbe.

At this point i've got about a foot of cable pulled out the rear and the front has disappeared out of reach down the front of the sunroof tube. The cable is completely stuck so I am unable to push it in either direction.

Anyone have an ideas how to salvage this project at this point. Thanks.

I should have said something before. I apologize.

right now, I am assuming the cable is garbage b/c you cut it. It may have been okay if you adjusted the clutch. Whatever, lets move on.

access the sunroof panel by removing the interior cover. To do this, slide the sunroof back about halfway and separate the interior cover from the exterior panel. Then pull it out of the front towards the windshield.

You will see where the cable interfaces with the sunroof once you push it forward a few inches (or totally closed).

Pull the cable out towards the windshield. (Watch out for grease@!@!@! yuk)

From there it should be self-explanatory, but I will try to keep up with the thread in the future.

Thanks. I've already gone through those steps without being able to get the cable out, which is why i resorted to cutting the cable in the rear and the other attempts I have made described in my previous post.

I apologize again. I don't know how I missed that.


It is in your best interest to force the cable out the front, somehow. The next option involves removing the interior trim componenents (headliner) and the rear driver's side trim so that you can access the metal tube that the cable resides in.


Some brainstorming: Vice grips, twist the cable as you push forward. Hammer and metal plate, use metal plate as an interface B/W cable and hammer. (git'r'dun!)

If you have access to a dremel, I would imagine that you could use the 'jewelers attachment' to reach the end to the cable tube and cut a few relief cuts into it.

Thanks all for the feedback.

Since the solid tube portion of the cable that I cut in the front is partially hollow I am considering getting a screw long enough to fit down the front of the guide tube and drive into the cut tube. This would give me something to pull with at the front.

I wont' be able to work on it till this weekend. I'll post when i've made any progress.

This should fix it up.
http://www.peachparts.com/shopforum/...9&d=1280620236

The tube flanges are what secure the tubing to the motor. The front tube is held by the flange in a slot and then clipped into the black clip. The rear tube goes into a white plastic piece and then clips on, once again held by the flange. The cable is toast. I would buy new tubes and a new cable. Don't know the shape of the motor, but it is starting out being 20 years old even before the jammed cable.

The sunroof is not easy to align again.

This evening I was able to drive a long screw into the cable from the front of the guide tube. I used a dremel to cut the cable in the rear and then pulling on the screw from the front I was able to easily slide the rest of the cable out.

So now where can i buy a new cable and the rear section of tube?

I might have misunderstood, but I thought you also cut the flange on the front tubing?

The tube is probably only a dealer item assuming it is still available, but a used one should be fine.

I do not like working on the sunroof (major pain) so I bought my cable at the dealer (still available) because I only wanted to do it once. I still have my old cable, which was fine, but I would buy a new one.

no, i didn't cut the guide tube in front, just the smaller tube in the rear, but i did cut the cable.

I've called a few local mercedes dealers and they don't sell just the cable, rather the cable and the tube.

Not true. The original part for just the cable was 126 780 13 89. It got superceded to 126 780 17 89.

Now that is for a 1991 W126.

The rear tube part number is 126 782 13 17.

As i say, i just returned the front tube to the dealer because I didn't need it. And I bought a cable and installed it. So I can tell you for a fact that the tube and the cable are bought seperate. There is not a combined number for the assembly.

Also, when you get the cable, all you get is the cable. You have to pry off the butterfly connector that attaches to the sunroof bridge and put it on the new cable. Look at it close and note the position of the little guide that slides into the slit in the tube and locks into the butterfly connector and put it back the same way. Pry open, position and squeeze back shut with pliers.

I was able to track down a cable and rear tubing from a 1979 240D.

Is there any reason the sunroof cable from a '79 240D wouldn't work in an '85 300D?

So I have cleaned out the tube, cleaned off the new cable, greased up the new cable and installed it into the tube. It slides very easily down the tube by hand. I re-installed the motor but it won't pull the cable through without assistance, i.e. when i push the sunroof button i hear the motor run and see the cable jerk a tiny bit, but the cable won't really move unless i push or pull on it.