DIY Sunroof cable replacement notes

GoodMojo · 07-07-2002, 01:34 PM

I replaced the sunroof cables on my 88 930 coupe over the weekend and thought some of my newbie experiences might be helpful for others who's thinking about doing the same project. The Pelican article, "Sunroof Repair", is a great read if you're planning to replace yours as well. For me, the total time from start to finish was about 5 hours with two beer breaks.

Since my sunroof was stuck in the closed position (cables broken), I used a stiff putty knife to "gently" pop
the spring clips (there's 6 or 7 of them spaced about 2 inches apart) holding the headliner to the roof. Be careful to not insert the knife too deep or you'll gouge the paint when prying the headliner off. Once the headliner has been detached, make a note of the channels that the headliner slides in and must fit into when reassembling (I didn't :/). Here's a pic:

The bolts the hold the roof to the mechanism are pictured below. Anyone know what the arm mechanism is for?

Since both of my cables sheared off from the guides and the shredded tips not visible in the cable guide tubes, I had to push the cable back out from the rear. Yoga training would've been handy here. I could've removed the cable from the rear of the guide tubes, but since the cables were covered in grease (more on this below), I didn't want to risk damaging the headliner. Once pushed back out, the tips of the cables should be fairly visible from front of the guide tubes. Using a grabber tool (its real name escapes me at the moment, pictured below), I grabbed the tips of the cables and eased them out.

The detached cable:

The tool that I used:

A few years ago, the PO had a local wrench grease up the sunroof mechanism which was presumably sticking at the time. The wrench dumped a truckload of grease on the channels, cable guides, and other choice areas. Whatever part that moved in the sunroof mechanism there was a big blob of grease to go with it. My guess is that the PO didn't use the sunroof often enough and the grease just made the situation worse and caused the roof to jam and snap both cables. I cleaned the channels throughly using just common dish soap, a sponge, and q-tips.

The new guides from Pelican are, as noted, the newer 964 style guides. I used a metal file and a Dremel tool to file the guides down to fit the older style channel. Unwinding the felt from the cables is an exercise in patience

I'd thought about just burning it off using a blow torch but the heat stress is probably not too healthy for the cable.

Be sure to fit the headliner back into its groove and the rear guide stops back into its channel when reinstalling the aluminum guide channels. Clear the rear drain holes of any visible blockage while you're at it. Move the guide back and forth in the channel to make sure there's no binding.

Reinstalling the roof: Make sure the guides are resting against the forward stops and the brackets are turned upward before installing the roof. Just common sense really, but easy to forget once the beer kicks in...

That's it. Pretty simple job really. Snaking the new cables back into the guide tubes was probably the hardest part of the whole exercise. The passenger side cable went in easily, but the driver's side cable was much tougher due to the shape of the guide tube at the rear of the roof. I just used the grabber tool mentioned previously to help push the cable into the tube.

Now if only the Seattle weather would cooperate so I can go and enjoy the sunroof today

-Wade
'88 930 Slant Coupe

Doug E · 07-07-2002, 05:45 PM

Great post Wade - thanks for the tips!

Sputterbug · Sputterbug's Garage

Definitely a good post. I have taken my sunroof apart 3 or 4 times; I replaced a cable and then had trouble with a small nut falling off one of the posts that raise the roof. The pic you posted showing the rearwards guts of the roof cavity - where the drain channel hole is visible - that's where the nut ended up. In fact, it entered that hole and fell into the channel. I blew it out with a straw from the exit hole (under the decklid).

Anyhow, the arms you ask "what is this?" about - they rotate towards the edge of the roof and are rested atop the thin cylindrical "spokes" that protrude from the cable guides. I think they aid with keeping the guides and associated assembly firmly in place so the posts can raise the roof.

GoodMojo · 07-08-2002, 06:58 PM

Ah, that was my guess about those arms as well. Thanks for the confirmation. I've returned them to rest on the bottom of the pins protruding from the cable guides and all seems well. Finally a sunny day to enjoy the roof

-Wade
'88 930 Slant Coupe

curlesw · curlesw's Garage

Great write-up. I have a similar problem and will need to undertake this project soon. Any idea if the sunrook is the same as a 82 SC?

Wayne C.
83 SC

Bill Douglas · 07-08-2002, 07:43 PM

GoodMojo, nice posting.

What's all this "unwind the felt" stuff. I didn't do this - should I?

Your "what this", I think it's so the bumps from the nuts and bolts don't catch on anything and the bit of headliner is held away from them. Just a guess.

Bill '79SC.

GoodMojo · 07-08-2002, 08:04 PM

curlesw: Maybe someone more knowledgeable about the SC's can chime in here, but the mechanism appears to be fairly similar. Check out http://www.pelicanparts.com/techarticles/911_sunroof_repair/Pic5.JPG. The channels and deflector are black aluminum on my 930.

Bill: The guide tubes on my 930 have a lot of grease in them from work done by the PO's old wrench. I was concerned that the new cables life would be cut shorter by the increased "drag" from the felt being dragged through the grease so I tooke them off. The Pelican article also recommended that the felt be removed as a precaution as well. If the cable moves pretty freely with the felt on while in the guide tube, there's probably not much to be concerned about.

-Wade
'88 930 Slant Coupe

Bill Douglas · 07-08-2002, 08:23 PM

Wade my 79SC sunroof with new cables didn't want to got all the way forward. I really don't know why. It stopped a couple of inches short of being closed so I pushed it by hand as someone else worked the switch. The "adjusted" new cables worked fine when tested so that wasn't jamming. Maybe it is the felt on the cables ?

GoodMojo · 08:43 PM

Doesn't seem like the felt on the cable would cause this. Is the sunroof moving smoothly throughout the entire travel up until it stops? Is the air deflector plate retracting ok and the sunroof transport mechanism (the cable drive gear) mounted firmly on its mount? One other thing I'd check is if the black rubber connector that connects the motor to the transport mechanism isn't falling apart (see this pic: http://www.pelicanparts.com/techarticles/911_sunroof_repair/Pic4.JPG)

-Wade
'88 930 Slant Coupe

Bill Douglas · 07-08-2002, 08:53 PM

Thanks Wade. I'll check those things. I pulled the fuse so it didn't get stuck open on a rainy day. So I beter find the fuse and put my thinking cap on. Bill.

Erakad · Erakad's Garage

Ok, I guess I'm cheap, but mine (83 SC) did the same last week. I disassembled the sunroof, and found the exact same cable problem as yours. As I said, I'm cheap - and besides, nothing ventured nothing gained. I took out the piece the cable connects to (slides off the track) cleaned grease off it and the cable, made sure I could force the cable into that transport mechanism, and then JB Welded the two together. So far, working strong with no hitches or problems. OBTW, also cleaned all the rails while I had it out...seemed like a good idea, and seems to run as smooth as ever!

My 2 cents