HOW-TO: Complete W124 Sunroof Refurbishment

[Efraim]

That was also in my mind. You confirmed it. Thanks.

 

[sheward]

I never got to use my roof much due to the unfinished business of installing a new cable. The roof did seem a bit tighter as I remember it.

drew

 

[Kyiv]

2 tools (124589182100, 124589172100) and larger felt pads (1247820030) are NLA.

I just received those on Friday

 

[mikeym]

I just received those on Friday
View attachment 128155

I thought they were NLA as well. Good to know that you were able to get them.

 

[Kyiv]

5: Get inside the car and roll the Sunroof lid fully forward again. Carefully mark the exact location of the brackets and fixing bolts before undoing anything. I use a sharpie and a scribe to mark them.

8: Back inside the car now start by undoing the 2x 8mm bolts that secure the Cable to the Transport Bridge. Then mark the 3x bolts either side and remove them also.

I'm about to start this job. Joe, explain to the idiot why the bolts need to be marked? I see in your picture you drew a circle around the bolt with a sharpie... Thanks

 

[gsxr]

I'm about to start this job. Joe, explain to the idiot why the bolts need to be marked? I see in your picture you drew a circle around the bolt with a sharpie... Thanks

I *think* the idea is, if you mark everything before disassembly... when you put it back together, you may not need to make any adjustments.

 

[Kyiv]

I *think* the idea is, if you mark everything before disassembly... when you put it back together, you may not need to make any adjustments.

I'm about to remove metal lid. When someone a lot smarter than me does something I need to understand. In this picture, Joe circled the washer and drew an arrow pointing at it. Looking at my own, I can't figure out how that's helpful...

 

[gsxr]

I think the ones on top can be removed without marking. Those just hold the roof panel to the side bracket.

Now, the ones on the side... those you don't want to touch if possible. If not replacing the lift arms, you can leave those alone.

 

[mikeym]

I'm about to remove metal lid. When someone a lot smarter than me does something I need to understand. In this picture, Joe circled the washer and drew an arrow pointing at it. Looking at my own, I can't figure out how that's helpful...

View attachment 128463

The metal lid needs to be centered. You can do it by trial and error by opening and closing it and see if it binds. If it is already working well, then just mark the existing locations and then when you put it back together, you have a starting point.

 

[Kyiv]

 

[mikeym]

One more thing. If you are marking stuff with sharpie/felt pen, be careful if you are cleaning up anything. I had use degreaser to clean some of the stuff which rubbed off a lot of the markings.

 

[Kyiv]

I think the ones on top can be removed without marking. Those just hold the roof panel to the side bracket.

Now, the ones on the side... those you don't want to touch if possible. If not replacing the lift arms, you can leave those alone.

View attachment 128484

Dave, those nuts/washers combos that are marked on your picture "Ok to remove without marking". I had 3 come out easily, but 4th had to mangled. Can you tell if #42 is the one? Thanks

 

[gsxr]

The nut+washer is #54, I believe... p/n 124-990-05-51. Odd that one was in bad shape!

 

[Kyiv]

The nut+washer is #54, I believe... p/n 124-990-05-51. Odd that one was in bad shape!

Indeed. Thanks!

3 of them untied easily and normally. 4th started stripping and crumbling right away (top right)

 

[Kyiv]

FSM says to use Gleitpaste on all the felt pads, and all moving parts of the lift arms. That's what I used, I did not apply oil anywhere.

@JC220, what's your rationale for using oil on pins and plastic bushings of lift arms?

 

[JC220]

@JC220, what's your rationale for using oil on pins and plastic bushings of lift arms?

Simple. No grease can penetrate the joints/ pins whereas oil does and the effect is immediately apparent.

Then the subsequent copious gliet smoo application will help lock that additional lubricity in place. (Kind of like using seran wrap on EZL paste)

 

[Kyiv]

So oil, and then gleitpaste to seal it in. Gotcha. Putting to use your write up!

 

[Kyiv]

Finally for ordering the parts please refer to the picture below – courtesy of W124 Performance. All part numbers and quantities are detailed thereon.



These little felt pads are very expensive from Mercedes – currently around £126 in the UK just for the pads.

I've gotten all of the above, except #140, parts. Looking at EPC and at my extracted lift arms and metal roof lid, I can't find where X2 of 1267820130 go. All the other ones I can account for.


These cover lift arms. 1267820130 is NOT used on life arms, per EPC:

Here is a pic of the parts for lift arms:






This part covers metal lid. Only X4 1267820130 need to be used. @JC220 specified total X6, with X2 to be used somewhere on lift arms... Where exactly?

 

[gsxr]

Pretty sure 126-782-01-30 goes here:



On a related note, did the tiny ones (124-782-01-30) have felt coating, or were they plain rubber? The ones I received from the dealer last summer had no felt fuzzies.

 

[Kyiv]

Pretty sure 126-782-01-30 goes here:
View attachment 128764


On a related note, did the tiny ones (124-782-01-30) have felt coating, or were they plain rubber? The ones I received from the dealer last summer had no felt fuzzies.
View attachment 128765

Indeed - thank you! And yes, those tiny sliders are plain rubber

 

[Kyiv]

Pretty sure 126-782-01-30 goes here:
View attachment 128764


On a related note, did the tiny ones (124-782-01-30) have felt coating, or were they plain rubber? The ones I received from the dealer last summer had no felt fuzzies.
View attachment 128765

I just replaced all those sliding pieces on both arms. Both smaller sliders (that are now rubber) were missing and one of 126-782-01-30 was missing from one of the arms. Rest were in place and although old and worn, they were far from gone. If cleaned up, they could be justified to be sold as "used, very good condition".

One definitely experiences a "high" cleaning lift arms from old grease and putting on new felt sliders

 

[JC220]

I just replaced all those sliding pieces on both arms. Both smaller sliders (that are now rubber) were missing and one of 126-782-01-30 was missing from one of the arms. Rest were in place and although old and worn, they were far from gone. If cleaned up, they could be justified to be sold as "used, very good condition".

One definitely experiences a "high" cleaning lift arms from old grease and putting on new felt sliders

Make sure and use a good quality super glue to fix all of the pads in place! Otherwise they will go missing again in future. Glued on and kept lubed with Gleit will keep them right

 

[Kyiv]

Make sure and use a good quality super glue to fix all of the pads in place! Otherwise they will go missing again in future. Glued on and kept lubed with Gleit will keep them right

It'll be a while before I'm qualified enough to have the arrogance to deviate from Your write-ups

 

[Kyiv]

Fingers crossed, thus far, the job has been a resounding success. Everything works after reassembly. Thank You, @JC220 for the write up with its encouraging intro! Those red Webasto tools are quite important for the job. I used just a smidge above 1/2 ounce of Gleitpaste for the job.

 

[zentoed]

Thanks to this write up, I just about finished servicing our 500E sunroof. But I have a question about adjusting the height of rear of the sunroof. Here's the situation. When I open and close my sunroof, the rear of the sunroof ends up a little low. When I use the tilt function and close the sunroof, the rear of the sunroof ends up a little high. So, when do I adjust the roof, after the tilt function or after the normal open and close?
I'm afraid if I adjust higher after normal operation, then it will sit higher still after closing from the tilt operation.
When it ends up low, I can put a little pressure from underneath and raise it a bit, and the same when it ends up a little high, I can push it down to level. It feels like maybe it is just friction with the gasket? The gasket has not been replaced, but the roof was just painted... I guess I need to find out whether the gasket was removed and reinstalled for painting.

 

[Kridre]

I have the same issue that I didn't fixed yet, I think that you need to push sunroof forward when tightening bolts.
That's why this tool exists.



Also are this two red tools for assembly really NLA? I think I can make STL file for 3D printing them in the future for everyone who needs them.

I already made connectors for headlights ventilation if someone needs.

 

[sheward]

Thanks to this write up, I just about finished servicing our 500E sunroof. But I have a question about adjusting the height of rear of the sunroof. Here's the situation. When I open and close my sunroof, the rear of the sunroof ends up a little low. When I use the tilt function and close the sunroof, the rear of the sunroof ends up a little high. So, when do I adjust the roof, after the tilt function or after the normal open and close?
I'm afraid if I adjust higher after normal operation, then it will sit higher still after closing from the tilt operation.
When it ends up low, I can put a little pressure from underneath and raise it a bit, and the same when it ends up a little high, I can push it down to level. It feels like maybe it is just friction with the gasket? The gasket has not been replaced, but the roof was just painted... I guess I need to find out whether the gasket was removed and reinstalled for painting.

Check for anything sticky that may have been left from painting. I didn't know about pushing the roof forward. Try that as well.

Thanks for that, Kridre!

drew

 

[sheward]

I could use two pairs of those vents.

drew

 

[gerryvz]

FYI... MB Classic shows these may be orderable, although possibly unavailable, so the order may be cancelled. Spendy buggers, $23+ list price, 4 total.

https://partssearch.mercedes-benz-classic.com/parts/A1247820030?tt=automatic

As Joe mentioned previously, these large rectangle pieces can almost always be re-used.

These are again available from MB. The part has gone to a new supplier, and the current (revised) part number is: A124782003064

 

[mikhanator]

If it breaks a lift arm and won’t open it’s a whole lot of trouble – I will detail that kind of repair in a couple months.

Hey JC220, turns out that's what happened to me and I assume my lift arms are broken as the motor still whirs and the right arm slightly moves but the left seems to have jammed completely during tilting. Do you have a link to your repair post by any chance?

 

[nehuge]

These are again available from MB. The part has gone to a new supplier, and the current (revised) part number is: A124782003064

So again, even if available, if old ones are in good shape can they be reused? I mean 20 bucks a piece geesh. Is the felt coating really necessary? Or can older ones in good shape that are mostly just rubber feeling do okay with gleitpaste?

 

[JC220]

So again, even if available, if old ones are in good shape can they be reused? I mean 20 bucks a piece geesh. Is the felt coating really necessary? Or can older ones in good shape that are mostly just rubber feeling do okay with gleitpaste?

Some can be re used yes. However in order to make this assessment you must remove your rails first then inspect the buffers and see which ones are worn / missing to order the minimum required if you wish to go that route.

This means a bit of a delay during the repair waiting on the parts VS proactively replacing them all when still available and keeping your reusable ones safe for future re use in a pinch when the spares inevitably go NLA. Aka I have a baggie of good w124 sunroof felts that can be re used in future. But my cars when serviced now typically get all new felts when the getting is still good.

 

[nehuge]

Also, if the grease on the sunroof cable was dry (my motor did spit my cable out about 8 inches, and I had to pull hard the cable the rest of the way out of the tube, and the grease on the cable was very dry). doesn't that also mean the tube itself is gummy too?

If I shot brake cleaner using its red straw attachment down the sunroof cable tube, would I risk the brake cleaner eating the nylon gears inside the motor?

 

[JC220]

Also, if the grease on the sunroof cable was dry (my motor did spit my cable out about 8 inches, and I had to pull hard the cable the rest of the way out of the tube, and the grease on the cable was very dry). doesn't that also mean the tube itself is gummy too?

If I shot brake cleaner using its red straw attachment down the sunroof cable tube, would I risk the brake cleaner eating the nylon gears inside the motor?

The old grease will be Dry in the tube yes but don't worry about that at all. New grease on the cable will pull in down the tube and it will work perfect. Don't bother with brake cleaner as it won't go far due to tube construction. It will leak and damage your headlining.

 

[nehuge]

Finally got the cable in I used a drill at very low speed to push and rotate at the same time it went right in
How do I remove this butterfly piece I already removed the pin not sure if that was necessary thanks guys

I know Ertech this is an old post and not sure if you are around, but how did you put a drill on the cable to spin it in? Mine has the butterfly end so there's nothing for the drill to grab.

Also, question for everyone else, how much force really should the cable be to push it back in the tube? Mine gets caught up on every curve and I use two hands to really push hard and it is stuck going through the tube. My entire headliner is out and I can see all of the tubing and it looks fine.

 

[nehuge]

Sorry to spam the board here (heh) but I did get it and here's some inputs:

I did get the cable in, and upon going back and forth with it I realized that the plastic sheeting over it had started to peel back causing it to bunch up and make its diameter larger and REALLY struggle to go down the tube. This is a new cable mind you. Question is, why did it do that? I think part of it was due to the fact that if you're pushing this cable in from the sunroof opening, you're sort of pushing it on a downward slope, and the top slot of the tube has sharp edges and is catching that covering and peeling it back. So I trimmed some of the peeled stuff back and thought "you know what, my W126 is also apart right now, I wanna see how this cable fits into its tube". And it went in wayyyyy easier in that tube. And not to get off on too many tangents, but stay with me here, I THEN thought "well actually, being a 560SEL the tube is longer for the longer roof and appears to take less drastic and more eventual bends than the shorter W124. That may be the reason why that cable was easier to push in around the bends." (plus the fact that the sheathing/covering was no longer bunched up by the time I tried it in the W126). So the lesson is, if entering the cable from the top of the roof, concentrate on only those first 2 or three inches of the cable entering the tube and keep that part SUPER flat and parallel to the tube. If you have to get inside the car, or reach up and over from the side while standing on the sillplate while the door is open to get to it intricately , then do so. I was just sort of standing on a step stool from the A pillar side with the doors shut trying to manage the cable all laying over my windshield instead of only concentrating on where it enters the tube. I also noticed that if you're pushing on the cable and it is somewhat getting hung up on the curves in the tube, the covering over the cable will actually slip and move along the cable to a different position on the cable. Mine had crept back on me and exposed a different physical makeup of the cable (if you go back to post #5, his picture with the orange gloved hand, you can see the that exposed cable has a different physical make up than the plastic covered section. If the sheathing slides to where it exposes that different type of metal spiraling, those are sharp and will really dig in around those corners of the tube and be difficult, gleitpaste on them or not.

Anyways, enough rambling, for us super nerds out there here is an interesting gleitpaste discussion if you haven't seen it before:

Modern grease longevity in application vs 30 years ago

I should add, for clarity, I do understand that a windshield wiper mechanism, however "sophisticated" doesn't require a "special" grease. However, when Mercedes specs Gleitpaste in WIS for sunroof, it's not that unreasonable to go with a recommendation, and use a left-over on a fairly complex...

bobistheoilguy.com

 

[nehuge]

Part 5- Re-assembly and final adjustments for smooth operation

This is the final section of the DIY which details re-assembling the sunroof and making some adjustments as you go to ensure the lid position is correct when closed and for smooth operation.

The adjustment stages are not 100% required but they are recommended when doing a full rebuild like this. To carry out adjustment you will need some vernier callipers (For centering the panel) and for setting the rear lid height adjustment a pair of regular 6mm drill bits are acceptable. If you have replaced the lift arms, sunroof lid or did not make complete markings of the bolts as you went then additional tools will be needed from Mercedes; (Courtesy of w124 performance)

View attachment 61793

I could simply say – “assembly is the reverse of removal”- which for the most part is true. However in the following steps I will detail the ‘full’ re-assembly and adjustment steps I would recommend-

1: Lubricate the section of rail pictured below of both sides with a light coating of Gleitpaste. Set the lift arms back in and slide them backwards out of the way

View attachment 62374 View attachment 62375 View attachment 62376

2: Lubricate the channel in the side trims as pictured and re-install.

View attachment 62377 View attachment 62378

Make sure the lift arm is correctly seated into the side channels-

View attachment 62379

3: Re-install the transport bridge and tighten the bolts back to the original markings made before removal

View attachment 62380 View attachment 62381

4: Re-install the gutter and don’t forget the little fibre washers first. Apply light oil to these connections

View attachment 62382 View attachment 62383 View attachment 62384

5: Now install the 4x remaining new felt pads onto the sunroof lid. I find it easier to Gleitpaste the back side first of each new felt pad then fit on and Gleitpaste the remaining sides.

View attachment 62385 View attachment 62386 View attachment 62387 View attachment 62388

6: Fit the MB tools both sides as pictured. (The tools are handed and marked L /R)

View attachment 62389 View attachment 62390 View attachment 62391

7: Set the Sunroof Lid back into place

8: Now to check / adjust the side to side placement of the lid in the opening. Loosen the front most 4x 8mm bolts as pictured (2x per side) Use the callipers to check both gaps and adjust as required before re-tightening the bolts again.

View attachment 62393 View attachment 62392

9: Re-fit the top sunroof lid nuts back on to the original markings made on disassembly.

View attachment 62394

10: Check the rear lid height. Mine was low both sides. Slacken the bolts pictured and lift the lid up to the correct height before re-tightening. This can take several attempts to get just right. Do this on both sides obviously. Then once set- remove the red tools both sides.

View attachment 62395 View attachment 62396 View attachment 62397

11: Now it’s time to fine adjust the sunroof lid front height in the opening. (This must be done now prior to the Stainless trims going back on) One screw as pictured both sides adjusts the front height. Again mine was low here too prior to adjustment.

View attachment 62398 (Note- I forgot this pic and took it after the trims were installed - it should not be adjusted with the trim plates on!)

12: Slide the lid back to open. Apply a light coating of Gleitpaste to the underside of the top stainless trim as pictured and re-fit the stainless trims both sides.

View attachment 62399 View attachment 62402 View attachment 62400 View attachment 62401

13: Now lubricate and adjust the front anti draught flap. Lightly oil all of the hinge parts and the top of the trim here-

View attachment 62403

Then there are 2x adjustment screws. This one adjusts the ‘stand up’ height with the roof open-

View attachment 62404

And these small screws adjust the flap in the lowered position as the roof is closing the last few inches. I find these always need tweaking to stop the flap rubbing on the lid as it closes.

View attachment 62405

13: Roll the lid fully closed and make sure both plastic brackets are positioned as shown below-

View attachment 62406

14: Re-install the fabric liner by inserting from outside. Set it in first – then check inside that the channel lines up before pushing it back in.

View attachment 62407 View attachment 62408

Roll the lid forward again about 3 – 4 inches and re-pop on the 4x plastic clips. Check that the fabric liner is correctly attached by using the ‘tilt up’ function of the sunroof. It may take several attempts to get both sides to ‘catch’ on the fabric liner brackets correctly. (It took me 4x goes on this one!)


And that is it! One re-assembled sunroof – and you CAN do it at home. It’s a half day’s tinkering for a DIY’er and highly recommended to do it sooner than later before the sunroof might stop working / jamb given that 99% of w124’s will have never had the felt pads replaced or the sunroof overhauled like this. If your sunroof is making any kind of scraping / groaning noises STOP using it until overhauled.

If it breaks a lift arm and won’t open it’s a whole lot of trouble – I will detail that kind of repair in a couple months.

You mentioned the side to side gap, but what about the front to back gap? It almost appears that the gasket is thicker on the back than it is the front, as if the roof is scooted toward the front a tad more. (less front to back gap in the front, and more front to back gap in the back).? Or is it the same gaps on the front as it is the back?

 

[nehuge]

Good points on the cable types guys a photo of both types is in post number 5 of this thread.

It's a great idea to nab spare late type cables at the parts yards since you can usually get them for next to nothing!

Hey guys see the attached video of the issue I have after doing a total sunroof refurb, new felt pads, the whole works.
I also used the red sunroof adjusting tools and the roof moves back and forth and tilts up/down great, but it won't push the air deflector down enough for it to get out of the sunroof lid's way in time. Anybody have any ideas? I know there is that tiny adjustment screw on those stainless steel lever/ramps but the screw is already maxed out. If I adjust the air deflector screws themselves where the roof lid will actually clear the air deflector, then the air deflector is too "flat' even in its popped up/raised position, defeating the purpose of it doing anything with wind deflection. See my attached video. Any ideas?

 

[gsxr]

Have you replaced the springs / clips for the deflector so it pops up fully, and then followed the FSM procedure 77-250 for adjustment? Are you sure there is nothing missing on the metal roof panel where it contacts the small side arms, that should be pressing them down further?

 

[nehuge]

Have you replaced the springs / clips for the deflector so it pops up fully, and then followed the FSM procedure 77-250 for adjustment? Are you sure there is nothing missing on the metal roof panel where it contacts the small side arms, that should be pressing them down further?

Yes springs and clips new and installed correctly. I AM the one having the deflector sit low because it is the only way to get the lid to skim above it and clear it.
The deflector pops up way high when I back out on it’s own adjustment screws as it should.
Felt pads under the lid itself are replaced. What about the white nylon little ufo shaped piece next to the get pads? How do I tell if they are worn? I don’t have a pic of a new one that has quality I can see that shows how thick they are new compared to mine.

 

[gsxr]

Something clearly ain't right but I'm at a loss to explain it. Maybe @JC220 has some ideas. If I'm reading the FSM correctly, the spec is 5mm air gap between the leading edge of the metal roof panel, and the plastic deflector, when properly pushed down during closing. I'll need to look at a couple of my cars for reference - never had the problem you're encountering.

 

[sheward]

My memory tells me that some mechanical arm or ramp lowers the deflector prior to the edge of the sunroof itself. I'm sorry I can't be of further help as my one sunroof is not completely reinstalled and the other car is not here presently. I do have a complete disassembled sunroof cassette here and can provide any particular pictures of parts.

 

[sheward]

I just had a look at the parts, and I see the arms or ramps have already been referenced.

 

[JC220]

Something clearly ain't right but I'm at a loss to explain it. Maybe @JC220 has some ideas. If I'm reading the FSM correctly, the spec is 5mm air gap between the leading edge of the metal roof panel, and the plastic deflector, when properly pushed down during closing. I'll need to look at a couple of my cars for reference - never had the problem you're encountering.

Yes I haven't had this issue either. I would surmise there must be something missing or broken on the deflector and it should be carefully inspected.

 

[nehuge]

Yes I haven't had this issue either. I would surmise there must be something missing or broken on the deflector and it should be carefully inspected.

I wonder if the two black metal prongs that the sunroof deflector has that the springs slide over maybe are bent? But then again that little plastic clip that holds the spring terminating end to the deflector wouldn't click in nor the prong slide through the spring if they were bent? Again sorry for late reply, work is kickin my butt and I'm getting to this as I can.

 

[larsko]

Thanks for this amazing guide! Two things: First: if you can’t move your roof back, don’t go for the “whole cassette” thing. Pull the inner panel down and bend it slightly to get it out, without opening the roof. That’s my take anyway…

Second. I had everything working, slide and tilt. Then I would, ever so slightly, adjust the rear height, loosened the two “horizontal” nuts on the bracket on each sidez Height is fine but suddenly it won’t tilt up anymore. Will look into that later, but hints are very welcome!

 

[nehuge]

Thanks for this amazing guide! Two things: First: if you can’t move your roof back, don’t go for the “whole cassette” thing. Pull the inner panel down and bend it slightly to get it out, without opening the roof. That’s my take anyway… Second. I had everything working, slide and tilt. Then I would, ever so slightly, adjust the rear height, loosened the two “horizontal” nuts on the bracket on each sidez Height is fine but suddenly it won’t tilt up anymore. Will look into that later, but hints are very welcome!

When you say pull inner panel down, do you mean the sunroof liner piece? Meaning pull the sunroof liner down out of the opening into the inside of the car instead of up and out of the opening of the car?

 

[gsxr]

I think he means pull the small panel down where it has 4 plastic clips to the metal roof, if you cannot open the roof fully to disassemble per the FSM procedure. And yes, it would have to pull down inside the car if the roof is closed.

 

[larsko]

Sorry 'bout the confusion. Think sunroof liner piece is the correct term, or sliding roof headliner. A1247800240
And it is meant to go up and out through the opening. But when the sunroof cannot open, bending it slightly and pull it down into the car, is a better option than doing the complete sunroof cassette disassembly. IMHO,

 

[nehuge]

So I figured out my wind deflector. I freakin' ordered one lol It works now. So something about that black pin that the springs slip over was slightly different enough to make a difference with the new deflector. All works now YAY!!!!!!!!