Speeding up That Slow Factory Sunroof

Speeding up that slow factory sunroof.

After putting up with the slow sunroof for quite a while I had enough of pushing it closed, I looked into what causes this and found that it is primarily because people use cheap non-Mercedes slide grease on it. Unfortunately I made this VFAQ shortly after doing my own so I don’t have any pictures of the crud that was left on the upper and lower rails. The grease was so solid it was easier to scrape it off then to clean it off with carburetor cleaner and a rag. Mercedes also has a document on how to remove the sunroof lid, it is 77-100.

Let’s begin! First step (you only need to do this if you are removing the sunroof from the vehicle) is to partially open the sunroof and pop that cover off, it is on there pretty good so be careful when doing this. I found it is much easier to get the headliner around the sunroof then pull it out through the top rather than through the bottom as then you bend the metal which isn’t good. There are six clips along the front which hold it; here is a picture of it unclipped.

After you get the sunroof headliner off (only done if you are removing the sunroof) the next step is to open the sunroof all the way so you can take out the screws which you see in the above picture. The only one that doesn’t get taken out is the slotted screw as that is the adjustment for height, after taking these four screws out that upper rail comes right off. Do the same for both sides, you will notice all of the gunk that has built up on the surfaces as I previously mentioned from cheap greases. After cleaning it up use the new MB slide grease with a thin layer on top and bottom of the surfaces that the slide touches. Use only Mercedes slide grease on these surfaces, it is specifically designed for these sorts of applications (it is also great for seat tracks). Just to mention this, yes the grease comes in a huge tub but that’d be quite a waste as you’d never use it. If you ask your parts supplier they normally can help you out, I got mine from Rusty for about $5 in a little stainless container.

Here comes a fork in the road, to the left we have that is good enough and everything under the sunroof looks fine, I’m going to put things back together now that I cleaned the crud out. To the right is, something here isn’t right or it isn’t clean enough yet, myself I had a bad slide in back and I also wanted to clean the bottom of the slides off as they get the crud on them as well. Read on only if you took a right (removing sunroof), otherwise you can just put the clean rails back on with their fresh MB slide grease.

Alrighty, you’re still reading so either you are bored or you really want to do this right. Go ahead and close the sunroof because we now need to work on the linkage which hold it there. With four bolts and a clip it is disconnected. There are the two bolts and a clip which the picture clearly show, then there are two more hiding in back that need to be removed. It seems to be the easiest way if you remove the rear two bolts first (while it is flush with the roof), then push the button real quick to make the sunroof drop down. Now take those front to bolts out and hit the button real quick again, the assembly you unbolted is moving on its own. That should have made it a little easier for you to pry the little clip out without damaging it, or at least keeping that to a minimum. Again push the sunroof button for open until the cable inside the sunroof is all of the way back. At this point you just have to lift the sunroof forward & out. It is doable with one person but two surely would make it easier at this point. Go ahead and clean those slides off and inspect them. Are any of the rubber slides cracking? How do the plastic ones look? If everything is peachy keen there then we are nearing the end of this venture, or at least this disassembly portion of it. Since my Teleflex cable (the cable which we unclipped and let run back a little ways) didn’t seem to have any problems with sliding I left that as is and just finished up cleaning the portions that the sunroof slide on.

used a gun cleaning kit for an 8mm rifle to run some patches down and clear out any old grease inside the tube here. I also cleaned off the outside of the tube you see running back towards the rear of the car. Again I replaced this grease with the Mercedes slide grease. Then I just went ahead and put everything back together reverse of removal. If you do feel you need to clean the tube the Teleflex cable runs in then things start getting a little bit deeper and messier, this is covered fairly well in the Mercedes document 77-140 which you can find on this handy online manual.

See picture of sunroof motor? Picture of motor with tube?

Tips:

Here is a helpful hint on getting the sunroof headliner to reclip, you have to hold it with force on one hand then hit the vicinity of the clip with a rubber hammer using the other hand such as the picture below shows.