REAR windshield seal W116, 123, 126
 

Notes and warnings...
This job requires 3 - 5 adult size helpers, pliers/razor, Philip's screwdriver, pliers, clothesline, and dish soap.
There should be NO cracks in the glass you plan to use, they generally will expand or the glass can stress and explode.
The seal should be replaced in a WARM location 70F is recommended, this is for seal flexibility and seating.
The body/seal mounting lip MUST be CLEAN, no dirt, old sealer, etc.
Your hands should be clean and dry, for maximum gripping ability.
The glass REAR windshield mounting lip/seal area MUST be CLEAN, no dirt, old sealer, etc.
This rear windshield seal procedure should function for the following chassis:
W201, 199, 198, 191, 189, 188, 187, 186, 180, 136, 128, 126, 123, 116, 115, 114, 113, 112, 111, 110, 109, 108, 107, 105, 100.
(there will be minor differences on the oldest chassis).
.................................................................................................



Procedure:

#1. remove the right and left rear paneling with cut-out for safety belt.

#2. Locate the rear windshield defogger connections middle of left and right C pillar, and disconnect them.
pic_1_rthdrhd.JPG

#3. From inside the rear passenger compartment, very carefully with pliers, pinch/nibble the old/hard seal, roughly 7/16 wide bites, (if the old seal is still soft you can use a razor knife to slice it away from the body/seal mounting lip.
Note: the inner seal lip must be removed from the top, and sides as close as you can get to the bottom of the windshield.
pic_2_rthdrhd.JPG
pic_3_rthdrhd.JPG

#4. Place a quilt or other thick cloth padding larger than the glass on the roof, or a totally empty work bench.
pic_4_rthdrhd.JPG

#5. This step requires at least three people, one in the back seat gently pushing out, two outside catching and lifting out the glass.
pic_5_rthdrhd.JPG

#6. Place the rear windshield on the quilt inside surface up.
pic_4_rthdrhd.JPG

#7. Remove the old seal from glass.

#8. Remove the trim from the seal, rolling the seal apart to not damage or deform your trim.

#9. Clean the body/seal mounting lip and glass mounting lip/seal area = no dirt, old sealer, etc.
Note: I prefer cloth rags and a good supply of clean water, no detergents/cleaners.
EDIT: I apply a light coat of plumbers putty to the body/seal mounting lip and glass mounting lip/seal area, it is almost the same composition as the MB sealer for 1/75 of the cost.

#10. Install the new seal to the glass.

#11. Exercising great care, flip over the windshield.

#11. Spread dish soap into the trim groove.

#12. Spread dish soap on the windshield trim barb.

#13. Install the window trim to the new seal.

#14. Install clothesline into the body/seal mounting lip groove with four - five inch overlap in the Bottom Center of glass seal, leave several feet of extra cord out beyond the overlap for hand pulling...
pic_6_rthdrhd.JPG
pic_7_rthdrhd.JPG

#15. pull the headliner over the upper lip seal area, and glue in place with trim adhesive.

#16. Gently lift the glass/seal/trim assembly.

#17. Insert the lower glass seal over the body lip, and gently lean the assembly against the window area.

#18. At least two assistants must gently press down and in on the glass while you pull the cords out evenly.
pic_8_rthdrhd.JPG
pic_9_rthdrhd.JPG

#19. The seal lip should roll open as the cord pulls out = allowing the seal to seat to the body.

#20. Use instrument cluster hooks to seat the outer perimeter of the seal.
pic_10_rthdrhd.JPG

#21. gently press/thump any trim areas not fully seated.

#22. Install the rear windshield defogger connections middle of left and right C pillar.

#23. Install the right and left rear paneling with cut-out for safety belt.


Additional drawings in post #2.

Additional drawings post #2.
 

Additional drawings post #2.

It's in the Wiki
 

This DIY is now in our DIY Wiki HERE.

Thanks Roy!

Thanks, Bill. I'm considering trying this on my SEC. Just the removal part, not reinstallation.

ok Roy,


I am lost. On the old seal and on the frame, there are tons of this clay-like gray sealant that is not water soluble. You do not mention using any sealant during the install.

Can I install the rear window without any sealant?

this is for w201. 1984

Yes
 

A light coat of plumbers putty. :)

yes!!

that is exactly what it feels like.

Perfect, thank you.

I'd like to ask what may seem like a stupid question about sealant.

You guys state here that sealant is not needed - but in the FSM it says that you should use it, and the following thread is a "special order thread" for the sealant:-

http://www.peachparts.com/shopforum/bodywork-repair-paint-tools-tips-tricks/207752-where-find-windshield-sealant-non-hardening-type-2.html?highlight=window+sealant

So can someone confirm whether sealant should be used or not?

Is it just a case that in dry parts of the world it isn't necessary?

I live in the wet so I plan to use sealant.

If I were to go for 3M products would this be the correct sort of thing?

http://www3.3m.com/catalog/us/en001/home_leisure/-/node_GSJ9WN519Mgs/root_GS2MT8MCQBgv/vroot_BWFLZ648DFge/bgel_SVHVD0DQNZbl/gvel_V81136SWNHgl/theme_us_chimpartnersupport_3_0/command_AbcPageHandler/output_html

Sorry found some more sealant links. Are these any good?

http://www.caswellplating.com/permatex/permsealants.html

and

http://www.goldtown-phils.com/adhesive/sealants.htm

The Zwaluw Auto Sealant is at least going to be easier to get here in Holland...

Answer
 

Never use any rubberized/silicone sealer.

You can order the MB# or buy a tub of Plumbers Putty at 1/4 the cost.
#1. Make a 3 MM diameter string of putty along the outer face of the body mounting flange.
#2. Smear the putty string on the body mounting flange, as a surface coating for the gasket.
#3. Make a 3 MM diameter string of putty, feeding it into the Body mounting slot.
#4. Make a 3 MM diameter string of putty, feeding it into the GLASS mounting slot.

I've recently removed the rear and front window on my W123 and I'm left with a putty removal problem... if it is soaked for ages in water it appears to be more willing to be removed - but this is only really practical on the lower edges of the window lip as the water can pool there.

Has anyone got any tips for a faster way of removing this putty? Sand paper kind of works but it clogs up quickly <= Only do this if you are repainting anyway!

Heat gun?

Or soaking rags draped onto the putty?

Suggestion
 

Use the steam function of an old clothing iron. :D
Takes a while, but it does the job.

Thank you very much for the tips - I ended up using a flat blade screw driver and wire wool on the car (sounds terrible I know) but there was no way I was going to try that on my tinted glass...

I'll give your ideas a go on the glass and report back - thanks again.

Thanks for this DIY write-up Roy. I read it over but I do not think that I need to pull out my rear window to fix a small leak I have in the lower right side. (What I see is some drops of water in the trunk when it is raining.) I had leaks in the lower corners of my front windshield and what I did was get the non hardening MB windshield caulking. I was able to slip the flat nozzle under the windshield gasket, pump in the caulking and it solved the problem beautifully.

I would like to do the same with the rear windshield but there is no room to get the nozzle under the gasket. Can I take out the chrome trim, which I assume is holding everything tight, get some caulking under the gasket, then replace the chrome trim? Before I start to pry, pull and possibly do some damage, I thought it would be wise to ask for some advice from someone that has had this apart.

Richard