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,

Attached Thumbnails

   

__________________
GC
1987 300E 104K
1984 300CD 112k R.I.P

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.

__________________
" We have nothing to fear but the main stream media itself . . . ."- Adapted from Franklin D Roosevelt for the 21st century

OBK #55

1998 Lincoln Continental - Sold
Max 1984 300TD 285,000 miles - Sold
The Dee8gonator 1987 560SEC 196,000 miles - Sold
Orgasmatron - 2006 CLS500 90,000 miles
2002 C320 Wagon 122,000 miles
2016 AMG GTS 12,000 miles

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!!

__________________
81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.

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.

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.

__________________
FRANKNBENZ

1985 300D "Old Blue" 265,000 (parts car )
1985 300D "Gray Ghost" 245,000
1985 300D "Silver Bullet" 160,000
1975 914 VW/Porsche "BC Car" 125,000
2010 Prius "Shocking!" 60,000
Text Message only: 301-728-1115

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

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.

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.

__________________
GC
1987 300E 104K
1984 300CD 112k R.I.P

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.

__________________
Houston, Texas
1984 300CD 235K miles, Elvira, one owner
1987 300TD 180K miles
1974 TR6 78K miles Sarah Jane, one owner
OBK #27

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?

To 300Turbo:
Unless you are a purist, key with the sunroof is to keep the tracks clean, the gearcase friction properly adjusted, and the motor end of the cable lubed with black lithium. I used beeswax on the roof tracks and on the headliner. Smoooooth....

To gcinque:
As indicated in my post, carefully disassembling the sunroof will make things clearer IF the problem is in that vicinity. Please use a Rubbermaid wash tub or similar to receive all parts lest they escape. Once the C-pin is removed from the front of the slide tube, releasing the forward end of the cable, nudge the switch to determine if the motor, gearbox, lower end of the cable are OK.

I also tore apart the motor/gearbox end of the system. The coged drive gear in there interfaces with the sprirals on the end of the cable, causing it to move. You may or may not have some broken cogs (gear teeth). Advise if you want inspection points to look for, R&R tips, photos, etc.

Good luck.

__________________
FRANKNBENZ

1985 300D "Old Blue" 265,000 (parts car )
1985 300D "Gray Ghost" 245,000
1985 300D "Silver Bullet" 160,000
1975 914 VW/Porsche "BC Car" 125,000
2010 Prius "Shocking!" 60,000
Text Message only: 301-728-1115

I was able to get the sunroof to open and close all the way with a little "help" just like Dee8go suggested . But before I did anything I sprayed Liquid Wrench using the little red straw it comes with and trying to get it as far on the rail as possible.

After waiting a couple of minutes I was able to open and close the sunroof with "help". It does not open and close all the way by itself.

The rails look great, I have attached pictures. Now that I can open it all the way I think I'm going to take it apart and inspect the cable and other parts.

Franknbenz, I would appreciate any photos and tips on doing this.

Thanks again for your help!!!!!

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__________________
GC
1987 300E 104K
1984 300CD 112k R.I.P

Good show on getting the roof open all the way. A good cleaning and lube is always a +.

Before you tear up the roof, try a small experiment in the trunk. I presume you already have the left trunk well plastic cowling up and out, exposing not only the sunroof power mechanicals but also that of the antenna.

With the cowling out, look at the motor...you indicted you broke off the plastic cap that looks like a 14mm hex head bolt. Under this dust cap is the finely-threaded gear shaft, the end of which should have two flats cut into it. Around this shaft and up against the gearbox housing is the adjusting nut, thin and 17mm (I think). The entire assembly is held in place by three 10mm bolts into a black multi-twisted bracket. This, in turn, is held to the trunk chassis by two more 10mm bolts.

Without removing anything yet, look at the shaft end. Imagine where the other end of this piece might be (out of sight up against the trunk bulkhead). Put a finger on the hidden end and, thumb on the flats, try wiggling the shaft. If it moves laterally, as mine did, that means one or both of base metal shaft support bushings are shot. Since I have a parts car, I swapped out motors rather than attempting to search for -- or have a buddy make -- these worn parts.

If no pronounced wiggle, try 1/2 turn CW on the adjustment nut, then get in the front and, helping hands at the ready, try an open-close cycle. If still slipping, try 1/2 CW more. Test again. If this adjustment makes things easier, break for a Molson's Export, eh?

If not, we will have to disassemble CAREFULLY the tubes, motor, and gearbox in the trunk and check on some other things. Always note any chatter (such as most rear windows develop). This means the spiral end of the cable is slipping on the cogged drive gear, it, hopefully NOT a toothless wonder.

Let us know how it goes, then we can together decide what's next. Finally we will pass on the maintenance routine, most of which has already been offered by others, but with some improvements learned at the University of Busted Knuckles.

Good luck.

__________________
FRANKNBENZ

1985 300D "Old Blue" 265,000 (parts car )
1985 300D "Gray Ghost" 245,000
1985 300D "Silver Bullet" 160,000
1975 914 VW/Porsche "BC Car" 125,000
2010 Prius "Shocking!" 60,000
Text Message only: 301-728-1115

I finally got around to work on the sunroof issue I'm having, I need to adjust the sunroof to open evenly.

When I open the sunroof the driver side pulls more than the passenger side. I can open the sunroof if I use my hand on the passenger side to help it along otherwise it opens only 2 1/8 inches on driver side, 2 inches in the middle and 1 3/4 in. on the passenger side.

Any suggestions on what to look for would be appreciated.

__________________
GC
1987 300E 104K
1984 300CD 112k R.I.P

Sounds like it is hanging on the passenger side track. Have you cleaned it out REALLY well and re-lubed it with white lithium grease spray? I tried using regular grease on mine at first and it was too thick makinfg the roof open/close really slowly and "hang" intermittently. Have you also adjusted the nut on the motor shaft like Frankenbenz suggested? That nut adjusts how hard the motor can pull before its clutch starts to slip. You want it adjusted to where when the roof stops moving in the fully opoen of fully closed position, the motor continues to turn (clutch slips) but slows down more than when the panel is moving. DO NOT OVER-TIGHTEN IT to where it stalls the motor when it stops moving. This can damage the motor, the gears, the cable, or (in my case) the cable housing (the previous owner did this to mine - just kept tightening it as it got sticker and slower and messed up the cable housing)

BTW, I never saw your thread until today or I would have told you that while you can't completely remove the headliner with the roof open only a couple of inches, you CAN pull the front edge down enough to get it to unclip from the roof panel and then slide it back into the rear section of the roof out of the way - giving you access to the mechanism. Once you do that you have much better chance of getting the roof most of the way open to where you can slide the headliner panel forward and out. You can even detach the headliner panel with the roof fully closed - I did - by slipping a very thin-bladed butter knife between the front edge of the headliner panel and the front edge of the roof opening and prying it down far enough to get my fingers on top of it and then pulling down on it enough to unclip it from the roof panel and slide it back. You have to be very careful not to damage the headliner vinyl though...

__________________
1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown

I used WD40 I also posted pictures of the rails, they are really clean no rust or debri.
Yes, but the motor pulls fine. It's just that when I open the roof slides back into an un-even position and it jams.

I found what I think might be the solution to this in the Service Manual CD#2, see attachment.

I'll try this tomorrow and report back.

Thanks ,

Attached Thumbnails

 

__________________
GC
1987 300E 104K
1984 300CD 112k R.I.P

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

__________________
'81 300D - swapped to a 617.951 turbo motor with a 150 amp alt.