Drooping Headliner Repair (Chet Hwilka - 7/22/02)

Overview

Over time and harsh conditions, the headliners in the coupes (and I suppose other models) start drooping or sagging.  This condition is seems to be accelerated by driving with all the windows down and sliding roof open, with all the wind turbulence in the cabin.  Mine started as a small patch (couple square inches) sagging in the back last year.  Throughout this spring and summer I've been driving with all my windows open (since installing the one-touch controllers, Bergwerks plug..) and the sag has gotten much worse (Fig-1). 
The interior headliner panel is composed of several materials.  First it starts with a rigid (heavy cardboard) shell that conforms the the inside of the car's roof and supports the headliner.  Then a rigid foam layer is applied to the cardboard that (I would imagine) acts as insulation to sound and to outside temperature.  Then the fabric/vinyl exterior surface, the part that separates and sags.  The rigid shell and foam layer very well bonded and I saw no signs of separation.  Around the perimeter of the sliding roof, the fabric wraps over the edge of the opening with a thin layer of foam rubber protecting the fabric.   The foam rubber is glued to plastic strips,  the strips are secured to the roof by metal tabs and the fabric is glued to the foam rubber.

Condition 

My headliner fabric itself appears to be in good shape (no tears, no real bad stains, not faded, etc). I felt I could simply reglue the existing fabric.  After cleaning the fabric a little. 


Started to droop Fig-1                                     Notice watermarks Fig-2

Tools/Material Required

2 - large cans on 3-M spray adhesive (medium strength  3M-08088)
1 - Medium grit sandpaper (for cleaning off the dried glue panel).
Resolve carpet cleaner (for cleaning the headliner - watermarks, dirt, etc)
Philip and straight screwdrivers.
WD40 (with extension tube)
Plenty of newspapers and a drop cloth (to protect from glue over spray)
Vacuum cleaner with brush attachment.
Several small clamp and/or strong spring clips to hold glued components in place.
Masking tape
1 - can adhesive cleaner (3M-08984)
1 - Roll of Scotch heavy duty double sided tape (Scotch 3M-4011-Long)

References

MB Manual CD - 
(68-435) - Removal and installation of Headliner (coupe)
(68-405) - Removal and installation of A-Pillar molding
(68-449) - Removal and installation of C-Pillar trim 
(77-050) - Removal and installation of Headliner for Sliding Roof
(77-110) - Adjusting Sliding Roof Cover

Disclaimer

The following procedure was done on my 1989 560 SEC and I can't say if this procedure will apply to other years and/or models.  This procedure worked for me and anyone else should use this writeup only as a reference.  Also this procedure may be different depending on the condition of your headliner and fabric.  Note that I made a few mistakes along the way and have noted them, hopefully making it easier for those that follow.

Removal

The whole interior headliner panel (or shell) is held into place by various trim and molding piece around the cabin.  The left and right outer edges of the headliner shell are tucked under rubber molding at the top of the side windows.  The rear edge of the headliner shell is tucked under the rubber molding at the top of the rear window.  The front of the headliner shell is held up in place by a separate vinyl front panel (forward of the sliding roof).  This front panel in held in place by the forward accessories (sunvisors and rearview mirror).  The left and right sides of the headliner shell are also secured by the hand grips mounted to the roof and behind the rear dome light is a clip that's screwed to the roof.
The items that had to be removed:
1. Hand grips left and right sides.
2. Rear dome light and bracket behind.
3. Sunvisors and securing clips left and right (caution, 12v always present if car equipped with lighted vanity mirrors).
4. Rearview mirror.
5. Left and right C-pillar panels.  (these are the side panel in the rear window parcel shelf area)
6. Left and right A-pillar reveals. (the manual call for it, but I didn't have to) 
7. Sliding roof headliner panel.
8. Left and right Sliding roof chrome side rails (4 screws) and chrome trim covers.
9. Cover strip at the front of the Sliding roof (6 screws).
10. Front Headliner Panel

Note: Before removing something, please make note of it's orientation and it's fasteners.  The are quite a few things that have to be remove and you want to make sure you get all the piece back in their original locations.

Remove Hand grips

Take a small flat-blade screwdriver and pry out the rubber cover that's tucked in under the escutcheons  at the end of the handles (Fig-3).  Remove the a small 8mm screw under the rubber cover.  On the passenger's side handle, gently pry off the plastic center cover (Fig-4) and remove that 8mm screw.


Fig-3                                                                           Fig-4

Remove the Rear Dome Light and bracket

Use a small flat-blade screwdriver on the car's right side of the light assembly and gently pop the dome light assembly out. (swings down from the left side)  Unplug the two power wires.  According to the manual, there's a bracket that helps secure the rear headliner to the roof (mine didn't have one).  If there, remove the screw that secures that bracket.

Remove the Sunvisors 

Unscrew the two phillip screws that secure the sunvisor swivel bracket to the roof (Fig-5).  Then remove the clips that hold the sunvisor in place (Fig-6).  Caution: These clip have 12v supplied all the time on cars equipped with lighted vanity mirrors.  Either pull the fuse or be very careful removing the screw in the center of the clip that secure the clip to the roof.  To gain access to the screw, use a small screwdriver to pry open the tiny cover.  (Note: Be careful to not rip the tiny cover off the clip as I did on one.)


Fig-5                                                                       Fig-6

 Remove the rearview Mirror

Now this could be a tough one.  The MB manual calls for, simply pulling down on the mirror to remove.  I pulled down with enough force to lift me out of my seat and that thing didn't budge.  I managed to very carefully work a large flat-blade screwdriver between the mirror base and attaching plate, trying to pry it off.. No luck..  I thought for sure this thing would break before I could get it off.. Then I remembered the shade tree credo, "If it's stuck and doesn't come off use WD40 and if it comes off, but should be stuck on, use duct tape.".  I very carefully, pried the mirror down enough to fit the WD40 tube in and gave it a very little squirt (didn't want WD40 all over the interior).  The mirror pull down and off with hardly any effort..
The mirror is secured be a pair spring loaded pins (Fig-7) that hold it to the mounting plate (Fig-8).  I guess with time the pin stiffen up a little making it difficult for them to retract enough to remove the mirror.
With the mirror removed, remove the 3 philip screws that hold the mounting plate in place.


Fig-7                                                                        Fig-8

Remove L/R C-Pillar Panels

To remove these panel you have to remove both rear seat cushions and backs.  The seat cushion is release by locating two levers under the front lower edge of the cushion and  pushing them in an outward direction.  Then lifting the seat cushion up and out.  Lift the back cushion off it's holders in an upward direction. (see job # 91-170).
The C-Pillar Panel is secured by a screw found hidden above the seatbelt retract spool.  It's hard to see, so use a flashlight and remove it.  Work the front edge of the panel from under the door trim molding with a flat screwdriver.  Then pull panel out in a forward upward direction.  Set panel aside without  disconnecting the seatbelt.

Remove L/R A-Pillar Molding

Work the rear edge of the A-pillar molding out from under the door trim molding.  Slip the A-pillar mould back and off.  Note: The manual calls for removing these moldings but, I was able to remove the front headliner panel off without removing the A-pillar molding..

Remove Sliding Roof Headliner Panel

Open roof 3/4 of the way.  Unclip the 4 push clips located at the front edge of the panel.  Use a 1-1/2 inch putty knife (or similar) and work it between the panel and the roof.  Locate a push clip with the knife and turn the knife to release the push clip. Repeat for the other 3 clips.  Hold the front edge of the panel down,  so the clips are clear of their holes and open the sliding roof all the way.  Now side the headliner panel forward and upward out the roof opening.  Note: Be careful to not get grease on the headliner fabric.

Remove L/R Sliding Roof Rails

In the area of the sliding roof, the headliner fabric is folded over the L/R edges of the slide roof opening and glued to plastic strips (Fig-11).  These strips are secure by metal tabs in sliding roof frame.  These strips are covered and secured by a thin piece of chrome trim (Fig-10).  This chrome trim is held in place by the slide roof rail cover (Fig-9).   
Fully open the slide roof, remove the four screws that secures the slide rail cover (repeat on other side).  Note: There are 3 small chrome sheet metal screws (back to front) and a single chrome machine screw found in the front.  DO NOT remove the adjusting screw found just behind the front-most machine screw.  Remove rail cover and chrome trim.  (Be careful, these components may be greasy, avoid getting grease on any fabric.)
Now carefully work fabric free of plastic strip on both sides.


Fig-9                                                            Fig10 (note adjust screw right)


Fig-11

Remove the Slide Roof Front Cover Strip 

The rear edge of the front vinyl segment of the headliner is secured under a metal strip located in the front of the sliding roof opening.  Remove the 6 screws that secure this metal strip and remove it.

Remove the Front Headliner Panel

With all the front accessories detached the Front Headliner panel can now be removed.  Start by working the L/R edges of the front headliner panel loose from under the top door molding.  Support the panel as it come down freely.  From behind the panel, push the front dome light assembly out and work it through and free of the opening in the panel.  Note: Unplug any wires if necessary to enable working the assembly through the hole.
Remove front headliner panel from car.

Remove the Headliner Panel

By now the headliner should be loose and down on the seat backs.  With all the windows down, carefully work the headliner out of the car.  Fig-12 shows that backside of the headliner panel, note the two tabs to either side of the rear dome light.  Mine had come loose and must be reglued. Don't loose them if they should fall off.

 


Fig-12 

 

Cleaning and Regluing 

Try not the pull the headliner fabric off any more than it is.  Having the fabric still somewhat attached to the shell will make it easier to scrub clean and hold in place as you are regluing it.   Find a nice big area where you can work, place an old sheet (or drop cloth) down on the floor.  Place the headliner shell down, fabric side up.  To clean the fabric I used Resolve  Carpet Cleaner.  I worked in small areas, spraying the Resolve and then scrubbing it in with a wet rag, constantly rinsing  the rag in clean water and completely wringing it out, until I cleaned the entire headliner.  I tried to get most of the Resolve out with the clean water.  I was also careful to not get the headliner shell too wet. When I finished an area I dried it off with a clean dry towel.  I was very pleased with the results.  I couldn't see any traces of the watermarks or dirt (especially around the handgrips) and managed to get most of a grease mark out.  I allowed it to dry for at least a day.

I started the regluing by pealing back the fabric, starting at the front to about 4 inch behind the slide roof opening (Fig-13).  One of the tricky parts of regluing the original fabric, is making sure all the holes and edges line up.  If you were applying new fabric, you could simply glue the whole thing down and trim the overhang off and cut out the holes.  Also the rear portion of the headliner (just above the rear window) is a layer of molded vinyl, that's glued over the fabric.  (I chose not to remove this vinyl portion and reglue it.  I simply glued the fabric/vinyl portion back down.  I hope I won't regret it..)
I carefully used a vacuum cleaner with a brush attachment to clean the loose old glue of the fabric and headliner shell.  I then practiced laying the fabric back down (dry) to see how everything lined up.  When I felt ready, I covered the exposed fabric with newspaper (Fig-13), neatly folded back the section I was working on and smoothed in out nicely.  I then set the glue can spray nozzle to "M" medium spray pattern and practiced spraying some scrap rags to get the feel.  I pretty much followed the directions on the can.  Be VERY CAREFUL to not spray the glue too heavy and make sure the can is spraying it in a nice light spray.  Otherwise the wet glue will soak through the fabric and it won't come out.  You'll have to live with these glue spots or replace the fabric.  (I should know, I did it. (see Fig-15)  I was too cheap and thought one can would do.  Ran short and had to use some heavy duty spray, which sprayed very wet.)
Make 2-3 passes in a cross pattern over both the headliner shell and the back of the fabric.  Let glue dry for 1-3 minutes and carefully lay the fabric over one edge, being careful to not tough any other areas.  (This stuff sticks real good.  A helper would come in handy here.)  Line up the edge and work your way to the hole.  Press every square millimeter with clean hands, until the whole half is recovered and perfectly flat.
When done repeat with the rear portion (Fig-14),  be mindful to align the molded vinyl section as it should be located at the rear of the shell.  Again (dry) practice makes perfect.

 


Fig-13                                                                      Fig-14


Fig-15

Rear Vinyl Section Revisited - (revised)

Well with my running low on adhesive with the first can, I missed a few spots where the fabric transitions to vinyl and sure enough a 2 square inch section let go.  It was hardly noticeable, but I knew it was there and it was my fault.  So I decided to remove the rear vinyl section and peel back as much of the fabric from the rear as I could (Fig-15a).  And then do it right.  Reglue the fabric making sure it was perfectly mated to all the nooks an crannies.  Then reglue the vinyl section, again making sure it was perfectly mated.  I also made sure every square millimeter of both sides had a good coat of adhesive.
It would be best to start by carefully peeling off the vinyl section while the fabric is somewhat attached to the shell.  Be very careful to not to stretch or tear it in the process.  It should come off rather easy, if the headliner was drooping because the glue was dried out.  Being that the backside of the vinyl panel is very smooth and still coated with old glue, I use the  3M Cleaner to get as much of the old glue off as I could (Fig-15a).  Especially at the edges that fit in the preformed grooves in the shell (Fig-15b).  You want to make sure there's nothing in the way of the new glue making contact the two surfaces.  That edge must set perfectly flush with the fabric in the groove.  You don't want the wind from the open windows separating the vinyl after time.


Fig-15a                                                                    Fig-15b 

After the fabric had time to dry overnight, I laid the vinyl section in place so every edge aligned perfectly.  Particularly the front edge that fits in the groove.  It should set down in the groove to where the edge of the vinyl does not stick out.  Note: You won't be able to properly seat that edge if the fabric was not properly seated in the groove.  So make sure you have a good coat of glue in the groove and on the fabric that fits in the groove.  Also make sure you don't stretch the fabric too much so it can't lay in the groove.  With the vinyl in place, I hold the vinyl down in place and take a very sharp pencil and lightly trace the vinyl edge on the fabric.  This gives me a line where I can lay my masking tape.  Since we'll be spraying glue to the top side of the fabric we don't want to get any on the visible area (Fig-15d).  You want the line between glue and no glue as perfect as possible.  You that glue right to the edge of the vinyl.  (Fig-15e)  To help position the vinyl panel after the glue is applied, I placed several pieces of masking tape at the edge of the vinyl and put alignment marks on both the vinyl and fabric masking tape.  (Fig-15c)
As with the fabric, I had my wife hold the material up from mating while I positioned and secured it. 

 
Fig-15c                                                                     Fig-15d


Fig-15e

 

Slide Roof Rear Track

The headliner fabric at the rear edge of the slide roof should overlap the opening by about an inch.  This excess fabric is glued to a plastic strip (Fig-16) and that plastic strip fits into a metal track built in to the roof (Fig-17).  I cleaned off the plastic strip, centered it to the rear edge of the sliding roof opening and taped it to the shell (Fig-16).  I then applied the glue, waited 2-3 minutes and secured the fabric to the plastic strip.  Note: As always be careful to not get glue over spray on fabric face.  

 
Fig-16                                                                     Fig-17

 

Slide Roof Corner Protector

The fabric at the rear corners of the slide roof is protected from tearing by a plastic corner molding that's glued in place (Fig-19).  You may find that the fabric doesn't align perfectly in the corners as it was originally laid out (Fig-18).  You may have a little extra fabric, if so, you'll have to cut the corner out so that it just wraps over the edge of the shell (Fig-19).  Dry fit the corner molding until it fits perfectly.   Then liberally apply glue to the inside surface of the corner molding and to the shell using a brush or Q-tip.  Fit the corner molding in place over the fabric in the corner and under the fabric overlapping edges (Fig-21).  Then clamp in place (Fig-20).
NOTE: After putting the headliner back in the car and wrapping this fabric back around the slide roof opening, I was not able to proper finish off these covers.  I believed I should not have glued them to the headliner shell.  Please take careful note on how yours comes apart...


Fig-18                                                                     Fig-19


Fig-20                                                                 Fig-21

Rear Headliner Clips

At the rear of the headliner shell, to either side of the rear dome light are two metal clips or tabs that are glued to the shell and clip into two slots on the metal roof. (Fig-21a)  These clips help hold the shell up.  These will have to be removed, cleaned and reglued. 


Fig-21a

 Reassembly

Before reinstalling the headliner it would be a good idea to do a little maintenance on the Sliding Roof.  Specifically, cleaning and regreasing the slide rails and any other moving/sliding parts.  Also blow compressed air through the drain hoses.  Refer to Maintenance Job 7730.

Start the reassembly by opening all the car windows.  Slide the headliner shell in the car.  Have a helper hold the headliner up in place about an inch forward, while you work the left and right edges of the shell under the rubber door molding. Then slowly push the headliner shell back so the rear tabs enter the holes in the roof and working the rear edge of the sliding roof into the track and then the rear window edge of the headliner shell under the rear window rubber molding. 
Note:
There's a lot going on here, so make sure everything mates up.  Have the helper handle the front while you handle the back.  
After the headliner is in place make sure the holes for the handgrips are aligned and if so install them in reverse order as the disassembly procedure.

Reinstall the vinyl front headliner panel, starting with working the dome light and roof switch assembly through the hole and then tucking the left and right panel edges under the rubber door molding.  Then install the sunvisors in reverse order of the disassembly procedure.  Note: Be careful to not short the power connection to ground (the screw) of the sunvisor clip.  Also be careful to not over tighten the screw securing the sunvisor clip as it will pull all the way through the clip. 

Remount the rear view mirror mounting plate making sure the small center visor is in place.  Before replacing the mirror, apply a little grease in the spring loaded pins.  This will make any future attempts of removing the mirror a snap.

Replace dome light/ switch assembly.

Regluing Slide Roof Left/Right edges of the Headliner fabric.

Clean the top and bottom on both sides of the slide roof where the fabric folds over.  On the Left/Right edges of the Sliding Roof opening, apply a length of double sided form backed tape. Make sure the tape wraps around the sharp metal edge of the roof opening. (The tape I used wasn't wide enough, so I use two pieces.)  The tape is used to secure the fabric and the headliner shell  the car and also to protect the fabric from the metal edge.  After the headliner shell is in place and secured in the back and on the sides above the door, peel back the plastic off the double sided tape and snuggly wrap the fabric in place.  Be sure the tape is securely affixed to the car and fabric.  I ran another length of tape along the top of the fabric secure the edge of the fabric to the car.  Clean and replace the chrome strips you removed in Fig-10.  
NOTE: Before you put the slide roof components back together, take the time to clean and regrease the slide roof rails.


Fig-21a                                                                    Fig-21b

When reassembling the slide roof slide rails, place the chrome trim that covers the fabric forward enough to where its end will be secured by the front edge trim when you install that.  Install the slide roof rail top so it secures the fabric chrome trim.  Note: Just behind the front most screw is the adjustment screw for the front height of the roof panel when closed. With the 4 other screws loose, adjust this screw until the roof panel set 0-1mm below the outer car roof skin. (see Job No. 77-110)

Position the Slide Roof front edge trim in place over the vinyl headliner panel's rear lip.  Hold all this snugly in place and replace the 6 small sheet metal screws. 

Reinstall the Slide Roof Headliner Panel

Fully open the sliding roof.  Slide the headliner panel in and down in place from the front outside.  Be sure the fabric side wing of the lift portion of the panel are lying free from tangling with anything. (Before installing, inspect the side wing springs, make sure they retract the wings fully when the panel is closed.)   Hold the panel at about 3/4 close and pull the front edge down slightly.  Then start to close the sliding roof, stop when the front pop-in clips line up with there respective hole.  Then snap the four pop-in clips in place.  The slide roof should function in all directions.

Done

I am very pleased with the way everything turned out.  Except for the little goof up at the rear edge on the Slide Roof, where the glue soaked through the fabric and the reassembling of slide roof corners (I'll be fixing that next).  (Before and After)  In the several articles I've read involving headliner replacement, the 3M 08088 adhesive is the way to go on this type of job.
I'm glad I went back and removed the headliner a second time and reglued the rear fabric and vinyl sections separately.  Now I can cruise with all windows and slide roof open without worrying about the vinyl separating...


Fig-22                                                                      Fig-23

 

Planning Summary

Headliner shell removal (at lease 2 hours 1st timers, otherwise less than 1 hr)
Unless you are familiar with the way the various panels and accessories are removed, plan a least 2 hours for removing the entire headliner shell assembly.  Start by removing the rear seats (cushions and backs) and the tray/box between the seats.  I make it a lot easier working in the back.

Headliner Fabric Cleaning (overnight to dry)
You'll most likely want to clean the headliner fabric if it needs it.  It'll take 30-40 mins to thoroughly scrub the fabric while it's still somewhat attached to the shell.  You should let it dry a little and make sure all the stains are out, otherwise go over it again.  Then let set overnight to thoroughly dry.

Stripping, prepping, laying out and regluing the fabric (2-3hrs and overnight for glue to dry).
Great time and care should be taken to not damage the fabric or vinyl panels.  Once you've stripped back the material, carefully remove any loose glue and make sure all surfaces are clean.  Then lay the material back dry and verify everything lines back up.  Apply adhesive to both surfaces (fabric & foam) and with an assistants help carefully resecure the fabric.  Let dry over night.

Reapplying the Rear Vinyl panel ( about 1-2 hrs to reassemble, 2-3 hrs to dry)
After the fabric has be give time to fully dry, its  time to reapply the rear vinyl panel.  Assuming you took care to clean the old adhesive off, proceed with the dry alignment of the panel.  Carefully mask off the areas you don't want adhesive on,  apply adhesive to both the back of the vinyl panel and the exposed fabric.  Thoroughly, secure panel, clean any excess adhesive and remove the masking tape.  Let dry for a couple of hours.  You don't want to catch the vinyl under something and peeling/popping it off.

Prepping sliding roof opening (about 1 hr)
Cleaning the old adhesive/foam tape off and reapplying new double-sided foam tape. This can be done while you're waiting to the glued fabric to dry.

Reinstalling Headliner shell (about 1-1.5 hrs)
Reinstalling the headliner (with help), resecuring the fabric around the sliding roof and reinstalling the accessories.  Should take 1-1.5 hrs.

Admiring a job well done (timeless)