Sunroof partially opens and closes...123 CD - PeachParts Mercedes-Benz Forum

gcinque · #1 10-02-2007, 08:12 PM

Hello all,

I just started having a problem with the sunroof, it won't open more than 2in. and it won't close all the way, 1/2 inch opening.

I have been reading some other posts and found out that to remove the headliner I need to open it more than the 2 inches.

Any ideas how to tackle this project without destroying the headliner and what might be causing this?

Thanks,

Dee8go · #2 10-02-2007, 08:15 PM

Will it keep moving if you "help it" with your hand? I have seen them bid up because of grit and rust or corrosion in the track.

carnut · #3 10-02-2007, 08:30 PM

In the trunk by the driver side trunk hinge is the sun roof motor. Should be a socket type tool there in a little saddle just in front of the motor. You insert that socket tool into the motor and rotate it with a reversable ratchet to either open the roof or to fully close it. Once open it most likely needs the rails cleaned and re lubed or the cable is stretched? If not there then a wreck should have it. Most dont even know what that tool does!!

KCM · #4 10-02-2007, 09:50 PM

Quote:

Originally Posted by carnut

In the trunk by the driver side trunk hinge is the sun roof motor. Should be a socket type tool there in a little saddle just in front of the motor. You insert that socket tool into the motor and rotate it with a reversable ratchet to either open the roof or to fully close it.

Carnut,

I believe by 1984 the tool was not needed as there was a hex nut/bolt built into the motor. Any standard metric wrench or socket should work.

FRANKNBENZ · #5 10-02-2007, 11:33 PM

The presumption is that the sunroof at one time worked well and now is not. Crud, rust, lack of lube may be factors, but perhaps we should consider some simple mechanicals.

One of my W123's was purchased with a weak sunroof retraction sequence. Last Saturday morning I tore that system apart and may be able to suggest a few things you might check, before doing anything with the motor, etc.

An issue may become clear if one analyzes the opening sequence in a fully functional system:
1. Button is pushed; motor activates, pulling cable into receiver tube in the trunk.
2. Forward end of cable is secured within a slide tube (housed between cabin liner and metal sunroof shell). It is the slide tube that may be the problem here.
3. At its forward end, the slide tube is carried through a yolk assembly -- a V bracket attached to the forward edge of sunroof metal shell.
4. At its trailing end, the slide tube fits over the cable guide tube leading under the metal roof, down the L/R roof support column, to the motor -- a tube within a tube.
5. At about its midpoint, the slide tube is fitted with a washer-like device welded perpendicular to the long axis.
6. At this midpoint the slide tube is carried through a horizontal strut. This strut is secured, L and R, to two cam plates.
7. The washer and the strut are joined with a U spring assembly, allowing restricted movement.
8. Cable pulls tube; tube moves washer; washer pushes U spring; U spring pulls horizontal strut; strut activates cam plates; cam plates lower aft end of sunroof metal shell; metal shell follows guide tracks into cavity between cabin and metal roof.

At the beginning of the opening sequence on your car, as the motor and/or your helping hand attempt to pull the sunroof assembly to the rear, stop at one inch. As in your photos, measure opening at L, center, R of sunroof edge. This, to determine improper alignment.

If it fails to open further, close it. Feel through the headliner vinyl for the horizontal strut. Activate again and feel for movement. Close. Activate again and gently attempt to aid by moving the strut to the rear.

There is one other possibility. The pop-up air dam has on each end a guide lever, L and R, pinned near the forward corners. The levers themselves are maybe five inches in length and at the rear are attached to pivot points in the sunroof gutter. Possibly one of these pinned areas may have become undone and the lever is jamming, preventing rearward travel.

Please try the mechanicals without forcing things.

If at the end of all that, you cannot determine the location of the jamming, the next step might be to remove the sunroof headliner. The photos appear to show about 1-1/2” of rearward travel. Look inside up at the forward edge of the headliner. That edge contains a metal strip upon which is mounted some sort of Masonite strip. Into this strip are set six or eight friction clips. these bond the headliner to the sunroof metal shell.

Seated in either forward seat, grasp the forward edge of the headliner about six inches on either side of the centerline, pulling down firmly, BUT with perfect control. The trick is NOT to pull down a distance greater than one inch. The clips will pop, center to the sides in order. Possibly the two on the extreme ends may still be seated. Work to either end and do these individually.

The objective is to gently bend the forward edge of the headliner into a shallow concave “smile”. This shortens the horizontal width and pulls the leading sides of the headliner out of its tracks. A larger smile, more of the headliner will come out. Now gently pull the headliner, still smiling, forward and probably down, over the dash. The normal SOP is roof back 2”, free clips, roof fully back, headliner up and out. I’ve done it up or down, same-same, just be careful.

Once inside, all the mysteries that once were the sunroof assembly should all be made plain.

Good luck.

gcinque · #6 10-03-2007, 09:05 AM

Quote:

The presumption is that the sunroof at one time worked well and now is not. Crud, rust, lack of lube may be factors, but perhaps we should consider some simple mechanicals.

Yes, the sunroof was workin fine until last Sunday. I have owned this car for 2 years now.

Quote:

I believe by 1984 the tool was not needed as there was a hex nut/bolt built into the motor. Any standard metric wrench or socket should work

Yes, I found it and broke the plastic nut/bolt, using this method allowed me to open the roof a little more. I read the Frankenbenz post "Gently try the mechanicals..." after I broke the part.
The sunroof barley clears the wind deflector. I ran I small screw drive between the sunroof and the wind-deflector to make sure that it wasn't caught somewhere.

Quote:

Will it keep moving if you "help it" with your hand? I have seen them bid up because of grit and rust or corrosion in the track.

Yes, with help of my lovely assistant I attempted to "help" the sunroof open but It keeps getting stuck leaving a 2-3in opening.

I will follow the instructions FRANKENBENZ posted and let you know how it goes.

Thank you all for your input.

123Guy · #7 10-03-2007, 11:57 AM

Once you get it working again, clean the tracks several times a year. You can spray them with WD40, wipe them clean and lube with either white lithium grease or something similar.
Also, periodically, do the same thing with your door latches - clean with WD40 and lube with lithuim - do that and you doors will continue to "snick" closed forever - unless that little plastic piece at the bottom of the latch fails, then you will need to replace the latch.

300Turbo · #8 10-03-2007, 08:06 PM

I recently went to local MB dealer to order a tube of sun roof lube. It would cost $24 so I said o.k. On way home the parts man called my cell phone and told me the new part # showed it to be $75 CHOKE !! COUGH!! COUGH!! He doubted I still wanted it and I agreed. What is a good substitute?

Sev · #9 11-02-2009, 12:30 PM

Quote:

Originally Posted by 123Guy

Once you get it working again, clean the tracks several times a year. You can spray them with WD40, wipe them clean and lube with either white lithium grease or something similar.
Also, periodically, do the same thing with your door latches - clean with WD40 and lube with lithuim - do that and you doors will continue to "snick" closed forever - unless that little plastic piece at the bottom of the latch fails, then you will need to replace the latch.

good info, i'd better do this the next time i get a chance.

will_t · #10 02-09-2015, 11:57 AM

Quote:

Originally Posted by FRANKNBENZ

Seated in either forward seat, grasp the forward edge of the headliner about six inches on either side of the centerline, pulling down firmly, BUT with perfect control. The trick is NOT to pull down a distance greater than one inch. The clips will pop, center to the sides in order. Possibly the two on the extreme ends may still be seated. Work to either end and do these individually.

The objective is to gently bend the forward edge of the headliner into a shallow concave “smile”. This shortens the horizontal width and pulls the leading sides of the headliner out of its tracks. A larger smile, more of the headliner will come out. Now gently pull the headliner, still smiling, forward and probably down, over the dash. The normal SOP is roof back 2”, free clips, roof fully back, headliner up and out. I’ve done it up or down, same-same, just be careful.

Once inside, all the mysteries that once were the sunroof assembly should all be made plain.

Good luck.

Is it possible to remove the headliner in this manner with the sunroof in the fully closed position? Mine is, and since operating my switch pops the fuse I would like to see if I can disconnect the cable and move the sunroof manually. Thanks!

Thecorrupterx · #11 08-21-2008, 11:22 PM

the sunroof itself rides just below the chrome uppers of the slide. you should remove the chrome plates and clean the bottoms of them and the slide path beneath them on the outside edge.

with the chrome strips out you could also get the roof into the almost closed position and lift up on the front and remove the front headliner clips and slide it out over the roof. this gives you access to the clip that attaches the sunroof to the sunroof cable.

once the clip is removed you should be able to carefully slide your sunroof up and out of the opening in your roof. give the plastic slider pads a good cleaning and lubing (or replace like my case). and also clean and lube the slide rails as far back as you can manage and lube them as well.

with the sunroof out of the way you can also check the cable for smooth movement.

good luck

tobybul · #12 09-01-2008, 06:10 PM

does anyone know if the spring is only available at the dealer?

BTW, there is no need to remove the entire deflector to replace the spring. The deflector will pop out on each end in order to replace the spring. Its best to do one end at a time.

9/4/08

Spoke with delaer today on that plastic slide support. Apparently, MB refers to the part as a "STAY".... and they just happen to have 2 of them.

I was not aware that the stay was a required part so I bent one of the springs to make it look like the orig. There appears to be no way to make the orig setup work. thats why MB deviced this new spring design and stay.

Daman858 · #13 04-29-2011, 12:22 PM

Whatever you do, do not bend that tube that the sunroof cable rides in. You will never get it straight again and it is a bear to replace.

I was told not to use anything but the MB sunroof grease.....clean the rails and other parts with alcohol only then apply the grease. You can get the grease in a small plastic container for much less than the dealer package, about $10 I think. Just google "Mercedes sunroof grease". The problem is that WD40 or lithium grease does hold dirt which makes problems for the roof.

skibummer · #14 04-29-2011, 01:12 PM

Quote:

Originally Posted by Daman858

Whatever you do, do not bend that tube that the sunroof cable rides in. You will never get it straight again and it is a bear to replace.

I was told not to use anything but the MB sunroof grease.....clean the rails and other parts with alcohol only then apply the grease. You can get the grease in a small plastic container for much less than the dealer package, about $10 I think. Just google "Mercedes sunroof grease". The problem is that WD40 or lithium grease does hold dirt which makes problems for the roof.

Not even sure where the tube you are mentioning is for the sunroof? Thanks for the advice on the grease. I find it hard to believe that Mercedes has created a type of grease that doesn't attract dirt and is not available at the local parts store as a generic brand. Is that really the case? Is it similar to the grease for mountain bike chains and gears (white lightening or clean ride) that supposedly attracts less dirt? It is more of dry wax or film than a grease. Thanks for the advice.

Daman858 · #15 04-29-2011, 01:18 PM

I don't know the properties of MB grease but I have been told by more than a few MB mechanics to use nothing but the special grease. The bicycle stuff is good for the radio antenna but not the sunroof.

The tube I spoke of is to the rear of the sunroof panel and it is what the cable from the motor runs through. It is pretty fragile and bends easily. You can't see it until you remove the headliner panel.