Sunroof all of sudden doesn't close

[dubadaddy]

My sunroof on one side of my car does not close all the way all of a sudden. It was working perfectly, however does not close all the way on one side now. I cannot use the tilt up part because of this.

Could this be a simple adjustment or is a broken part?

Any ideas?

[biking4jesus]

make sure everything is well lubed.

[compress ignite]

IF, Cleaning and the Gleitpaste does not "Fix" it.

GSXR has a Tutorial AND Pictures.

http://www.w124performance.com/images/W124_sunroof/

BUT,BUT,BUT...You Want to "Study Up" on Mercedes Sunroof Repair,
A LOT!

A Dealer R.O. that has the word SunRoof on it STARTS at $1,000.00 USD.

[JohnM.]

Originally Posted by compress ignite

IF, Cleaning and the Gleitpaste does not "Fix" it.

GSXR has a Tutorial AND Pictures.

http://www.w124performance.com/images/W124_sunroof/

BUT,BUT,BUT...You Want to "Study Up" on Mercedes Sunroof Repair,
A LOT!

Looks like not a lot of fun.

[compress ignite]

Guaranteed needed on most Old W124s:

1.Sunroof Cleaned and Lubed. [AND the Cable and Tube (Yuck!) ]
2.Mono Wiper Gearing and Sliding Tubes cleaned and lubed.

[Bonus 5 minute Job ANY Bright Saturday ,Clean and Lube the Antenna Mast.]

No One Ever alluded to Mercedes Ownership Being "FUN".
'More like a couple of High Maintenance Wives.
(Who,When Bored,Screw with your Karma for their Fun.)

[duxthe1]

I'd say that hardly anythng is "simple" in that sunroof. I've worked on MBs for 15 years and I cringe whenever I get an early sunroof to repair. In fact the fuse has been out of my 124's sunroof from the day I bought the car. Unrelated, I pulled the fuse for the rear windows as well.

At the indie shop, we tell people that if you don't have $800 to spend we're not gonna touch it.

[compress ignite]

Hi all,

Last fall, my sunroof made a sickening noise when I went to pop it
open one day. I managed to get it closed, and left it alone until I
had time to work on it, which was last week. One of the angular
lifting arms, which are the fancy mechanical pieces that allow the
sunroof to both slide open AND pop upward, had broken. And when I took
things apart, the other one broke during disassembly! I had heard all
the stories about how this is not a DIY job, and is best left to the
dealer for $1000+ in parts & labor. But, being the tightwad that I am,
I figured I'd try it myself first... and if I screwed it up, I'd have
to let the dealer fix it.

The worst part is getting the sunroof disassembled with it broken.
Normally, the first step in disassembly is to open the roof fully,
then remove the liner and front rails. Well, that is not possible when
the mechanism has broken. (See below for tips on how I did it in my
case.) After getting the trim panel out of the way, I could see the
nuts that were to be removed. I scribed marks around these so I could
re-assemble in the same position later. With the metal roof removed,
the hard part is over, then it's just a matter of carefully following
the factory service manual procedure - which, I must say, is a little
vague in some areas. I also marked exactly where the lift arms attach
to the "transport bridge", the wide section that the sunroof cable
attaches to.

Once the lift arms, drip rail, and bridge are removed, you need to
clean everything up and then re-assemble. The procedure said to lube
moving parts of the lift arms with Gleitpaste (special sunroof lube),
which I did. It also said to lube the rails, and the felt pads on the
lift arms, which seemed weird but I did it anyway. It looked to me
like the felt pads would be fine with no lube, but oh well.
Installation was relatively straightforward. I had the pliers to pull
the metal roof forward, but I really don't think they're necessary.
The small plastic gauges are needed, and come in handy, but it took
some head-scratching to figure out where they attach. I forgot to take
a photo of them in place - wooops. When putting things back together,
I used the marks I had made when taking things apart, and it turned
out quite well - I didn't feel the need to do further alignment, it
looks fine. And it works perfectly! I was a pretty happy camper by
this point.

If you are just taking the roof apart to clean it, the only nuts that
need to be removed are the 2 on each side with the wide washers that
attach the metal roof to the bracket on the lift arms. There's no
adjustment here, no need to mark them, AFAICT. It's the two small
screws on the side that attach the bracket to the lift arms that allow
vertical adjustment for the rear of the roof - leave those alone
unless you're replacing broken arms. The other important ones are the
6 screws that attach the arms to the transport bridge. Mark the
position of the arms on the bridge - I just scribed a line along the
edge. This is less critical, IMO. Don't mess with the nuts on the
front of the metal roof panel.

The EPC indicates that the old lift arms have been superceded by new
improved lift arms for early VIN numbers only - the break is the
mid-1987 model year, and of course I had the early style. In my case,
I needed both sides (at $100+ each), plus a new drip rail, new metal
guide rails, and - allegedly - a new cable. However, you don't mess
with the cable at all. The cable design was also changed, and the EPC
says the old part "must no longer be installed". I'm guessing that MB
figures if you're doing major sunroof work, this would be a good time
to upgrade the cable too. However, it's not *required*. I already had
the new cable, and figured I might as well go for it. It takes quite a
bit of force to remove once it's run out of the motor, and kind of
"jerks" out in sections - it seems to hang up periodically. Installing
the new cable was awful - I almost thought I was not going to get it
back in. With a friend helping to twist the cable, and me pushing, we
finally got it back to the motor and it pulled the rest of the way in
normally once it hit the motor drive gear.


Disassembly tips:
==============
This worked on my car, but I can't say it will always work - I don't
know what the usual failure mode is:

1) You have to get the liner/trim panel off the sunroof. There are 4
plastic press-in clips near the front that must be popped downward. I
was able to partially raise my sunroof, and pried it up by hand as
best I could, propping it in position with whatever won't scratch the
paint. Then, through the maybe 2-inch opening, I could shine a
flashlight in to see above the liner panel. I used a long (24-30
inch), flat (3/4" wide by 1/16" thick) metal bar to wedge in between
the metal roof, and the metal frame of the liner panel. This is VERY
HARD to do unless you can look at another 124 with a good sunroof, and
pop the liner down (with the sunroof opened) to see how the clips
attach! Otherwise you can end up prying between the wrong pieces, like
I did, almost damaging the very expensive trim panel. Once I figured
out where to pry, I got the panel popped free, and could then slide it
backwards and see the bolts on the underside.

2) With the liner out of the way, you can remove the two nuts with
attached, wide washers. This allows the rear of the roof panel to pop
pretty far upward. However, the front is still hooked under the rails.
Remember, normal disassembly specifies to open the roof, *unscrew the
rails*, then close the roof. With the rails out of the way, the roof
simply lifts off with the 4 rear nuts gone. But not in my case. Since
the roof is now separated from the lift mechanism, I lifted the rear
up and manually pulled the roof back. It only moves a couple inches,
but that's all you need to reveal the front guide rail screw. Remove
the screw (both sides), push roof back forward. Lift the roof upward
and prop it up with something that won't damage the paint. You can see
the remaining 4 rail screws on each side. A small, flat, ratcheting
screwdriver is what I used to fit in the very limited space to get the
screws out. With those removed, the whole metal roof now lifts off the
car, and the guide rails are also removed. The rest of the job follows
the factory procedure.


Anyway, in summary, it wasn't nearly as bad as I thought it would be.
And, I had no major alignment issues afterwards. Between using the
plastic guide tools, and marking the bolts, it was quite painless. If
your 124 roof is starting to act up, and you plan to keep the car long
term, I'd almost consider proactively replacing the lift arms (and
other parts) BEFORE they break. It will be a far easier job if you can
still open & close the roof - trust me. The cost of parts are,
roughly, $100 each for the arms, $70 for the new style drip rail, and
$15/pair for the new style rails. The new cable isn't needed, but will
be $60 or so if you want to do that too. Prices are based on current
wholesale, Dec-2005, and of course are subject to change, etc. If your
car is after VIN #A354333 (for sedans), you probably don't need all
those parts, just the lift arms, which appear to be the
fragile/stressed item.

I'd almost say it's not that bad of a job to fully disassemble a
working sunroof, for a proper cleaning (note all the greasy crud on
the old arms in my photos), lube, and re-assembly. Just don't force
anything - it all comes apart without major effort (except the sunroof
cable replacement, which I would avoid if possible.)


Photos are here:
http://www.w124performance.com/images/W124_sunroof/

If I ever do this again, there are a couple things I'd like to add
photos of, like what the plastic install guides look like when
inserted, etc.

=)


Best regards,

--
Dave M.

[compress ignite]

I did one, seemed pretty simple.

Start with the sunroof panel in the fully closed position.

With the panel down, remove the two bolts holding the cable to the carrier frame.

In the trunk, look at the two knobs on the motor/drive. One is round, the other hex. Pull the round one out until it pops into the outward/disengaged position.

You can run the cable out manually, using the hex drive, 17mm (lug wrench size) if the clutch isn't set too tight (many are too tight). In this case simply rotate the hex until the cable is far enough out that it is disengaged from the drive, then pull it out from the sunroof end.

I installed reverse of this, lubed and fed the new cable down into the tube until it hits the drive, then turned it down to the point where it lined up with the bolt-holes that secure it to the carriage. I bolted it on, pushed the round knob back into the engaged position, and all was well.

If your cable was broken, extracting it might be a little more difficult. You will also need to adjust the stop point of the sunroof, which seemed quite easy also IMO:
My method was to run the sunroof closed using the switch. It will stop when the stop-position is reached in the motor. Then I pulled out the round knob, ran the sunroof to the proper closed position using a wrench on the hex, and re-engaged the round knob. Worked great, ... the manual was at home and I was in too much of a hurry to go home for it, so I created my own method.

Another thing: The hex-shaped plastic hides a smaller hex and a lock-nut. This is the adjustment for the slip/clutch in the system. If it is too tight (sounds like yours is if it broke the cable), adjust it.

Disclaimer:
The manual probably has a more precise 30-step process for this, and it is most likely better than my method in some way, you will probably be ahead to read and follow their instructions. This also is from memory, ... your mileage may vary.

Another note: If the whole thing won't work, you can reach the two bolts securing the cable to the sunroof carriage through the tip-up vent panel. Use something to protect the headliner material as you work, but it is a way to manually open the sunroof and then the interior panel if the cable is completely bound up or otherwise unable to move the sunroof panel.

[compress ignite]

Mercedes started installing the tilt/slide roof in the 201 & 124 in '86/'87. My '91 126 had the tilt also, I don't know when it started. The roof prior to this is less troublesome, as the tilt mechanism is often the problem and many people on the Diesel list repair and then avoid using the tilt feature. It isn't an impossible repair job, but it does take a special tool (searching on the diesel forum for 124 sunroof might yield the applicable threads and details on fabricating the tool) and an entire day once the parts are procured.

As far as binding, the cable is often the cause there, it is the first place you should look IMO. You can on the 124, 126, and 201 detach the front of the cable from the sunroof carrier by pushing the tilt/vent panel up and working carefully through it, the cable is the two 8mm(?) bolts just rearward and centered. The cable can be threaded out through this panel without opening the sunroof and removing the inner panel (which is the FSM proceedure) if you're careful and protect the headliner panels from damage (cut easily).

If the sunroof drive cable does not move freely, it is most likely the cable grease, which is a pretty intuitive cleaning/re-lube process, using a rifle-cleaning brush to clean the tube as far as possible.

The cable lube past is available from Phil/Fast-Lane above in small quantities. I've had good luck with pure silicone grease (Plumber's Grease from hardware) as it has similar properties to the M-B lube, but to each his own, the OE stuff is pretty cheap if you're waiting for parts anyway.

You will need to disengage the switch mechanism to do this, here's my next shortcut, use it at your own risk:

To service the cable, I close the sunroof completely.

Next I pull out the plastic knob on the sunroof motor assembly to disengage the limit switch.

Open the vent/tilt panel in the sunroof, protect the edge with a good thick rag, and remove the two bolts so that the cable is unattached from the carrier.

Now I use the manual crank (per owner's manual in your glovebox) to run the cable out into the cabin of the car until it disengages the drive gear.

After the cable is no longer engaging the drive gear, you can pull it out into the cabin. It is greasy, keep a towel or other item in the cabin to protect the interior, simply threading it out through the window with a towel on the windowsill works. Keep the cable as clean as possible, grit will cause big problems.

Clean the guide tube which is immediately rearward of the cable attachment point on the carrier. Be careful to not be so forceful that you kink the tube, that will require headliner removal, which means the rear window etc., ... you want to avoid it.

Clean and lube the cable, and re-insert it until it stops feeding in, you're now against the drive gear.

Carefully, turn the manual sunroof override to retreive the cable into the tube, a second person is helpful here to keep the cable clean as it is being fed in. If it binds when starting, pull the cable back an inch and re-insert.

Once the cable is lined up perfectly with the bolt holes, bolt that sucker in.

Push the knob back in (hopefully you haven't turned it during this process) to re-engage the limit-switches. If all of the planets and stars are aligned for you, the limit switch will still be properly adjusted, and the sunroof will stop in the completely closed position. If not, you can run it until it shuts off in the closed position, pull the knob out, manually adjust the position of the sunroof using the manual-override nut on the drive, then re-engage the knob/push it in.

This has worked for me on a couple of cars, it is NOT the long and difficult procedure in the FSM and doesn't require any special tools, which is why I do it this way. Your mileage may vary, do it at your own risk.

This is also completely from memory, so if I have left something out, please correct me.

One other important point: If the manual override on the drive seems to be very hard to turn, don't. Loosen the lock-nut on the unit to reduce clutch friction, there is an adjustment procedure, ... I don't remember, but two of mine had clutches so bound up you could not manually open/close the roof without (most likely) damaging the gears in the drive.

Good luck.

[just-n-time]

Ok with all the voices not one said anything about the obvious troubled spot with the sun roof. When ever you have one that fails to close properly, say one corner is up slightly look to the rubber gasket that seals the area for a water tight leak proof sun roof. very often the gasket has pulled out of the lip it rides in, and this will prevent the roof from setting in its proper location. The more you try to force it to close the greater the chance of destroying one of the guides, or side rails.

[locry]

It's really not that complicated once the sunroof headliner is out... quite easy to remove everything.
I had to "gut" mine coz both sides of the mechanism decided to disintegrate... jeez. I'm temporarily reinstalling the sunroof and using what's left of the two rails just to fasten the metal roof to the opening. Off to find both the left and right tilt/slide mechanisms... anybody got any leads? used or otherwise will do. Thanks