DIY front and rear windows install ? W123 - PeachParts Mercedes-Benz Forum

rhodes2010 · #1 01-23-2006, 03:26 PM

Has anybody replaced front and rear windows on a W123 chassis ?

The book makes it seem do-able. Greasy string around the rubber,
sealant to keep it from leaking.

I think paying the local guy his $75 labor per windows is cheap insurance
for a tight leak-free fit. But if somebody can tell me that is goes pretty smooth
I'll do it myself.

I do not need the glass, just the rubber.
There are no leaks, but the rubber is dry and cracked and looks bad.

Pete Burton · #2 01-23-2006, 03:27 PM

I did the rear on my 126 myself, but only because it leaked.

rwthomas1 · #3 01-23-2006, 03:58 PM

If they can guarantee not to break the glass and there won't be any leaks then I would sign the check. RT

pdxwaker · #4 01-23-2006, 04:21 PM

Quote:

Originally Posted by rwthomas1

If they can guarantee not to break the glass

I'd be surprised if you could find someone willing to guarantee this...

Brian Carlton · #5 01-23-2006, 04:23 PM

Quote:

Originally Posted by pdxwaker

I'd be surprised if you could find someone willing to guarantee this...

For sure......they won't guarantee anything unless you purchase the glass and have them install it.

Let's face it..........you can't guarantee a $300. piece of glass when you are only getting $100. for the install.

Mismost · #6 01-23-2006, 04:27 PM

I did auto glass back in my younger years....never did a MB, but the "rope in" method is pretty much as simple as it sounds. In fact getting the old seal out without breaking the glass is going to be the hardest part.....it is a kinda pry and push gently out routine...when in doubt, razor it out...go slow and easy.

It really helps to have a HELPER on this job, a gentle helper! Assuming you have the glass out in one piece...

1. really clean the edge of the metal the new gasket will seat onto...good time to apply primer, sand off rust...just get it clean and soap it up

2. wrap the new gasket around the glass and soap up the inside that will be pulled into the car and the groove that holds the rope....we used a nylon rope about 3/16" (not a string, but maybe your gaskets are not as large...be sure and use a good stout nylon trotline or mason's string)....soap the rope too

3. start the rope in the bottom middle of the glass and wrap it around the gasket...should have two ends hanging down in the middle on the bottom...now use some strips of masking tape to hold everything in place...the rope will tear right through the tape when it gets there

4 it helps to have a couple of nylon push sticks...you could wittle some outta wood, 1/2" wide, 8" long, 1/4" thick, shave down the end to a flat tapered rounded edge...shape so you can use it to get in behind the gasket and the frame to help ease the gasket around...you'll see what you need. Don't use a screwdriver! Metal breaks glass pretty fast.

5. Set the gasket on the bottom of the frame and center it into the opening...if you soaped up good things will slip around easy....start pulling the rope out towards the corners...you will quickly see how and why the rope works! Get the bottom corners in place and started up the sides...Now PUSH the glass down onto frame as you pull the rope so the gasket slips over the frame

6. Start up the sides, gently pushing the glass into the frame...go easy, work with your stick to help ease the thing in....don't work yourself into a tight bind and start forcing your way

7. Top corners are gonna be a little tight....you should be able to eyeball and tell if you have enough room or if your glass is sitting to high (push it down)...keep pushing in and pulling the rope....use your stick to ease the rubber around the frame....you should be done now!

A spray bottle of soapy water or glass cleaner is helpful....lube it up, when it's tight spray it down....cleaning up soap and water is easier that cleaning up broken glass! Once the rope is out and the gasket is inside the frame, you may need to kinda slap (gently!)the glass down into place.

Glass is tougher than think, but it is still easy to break! If you have done a few hundred installations, this is a piece of cake, a 5 minute job....first timer, maybe 20 minutes. Just go slow and easy, watch what you are doing and protect the EDGES of tempered glass at all times! You can bounce a good sized rock off the face of tempered glass (sometimes) and bump the edge with the ring on your finger and shatter it....in fact, if the glass is really cold, the thermal shock from the heat of hands can shatter it!

Good Luck! And if you break it....well, it ain't the first time that has happened!

PatricdeBoer · #7 01-23-2006, 04:44 PM

I replaced my rear window on my 76 300d and I have one word of advice. NEVER.....NEVER.....NEVER!!Even think about using any seal that is not OEM. You will be flayed with misery and woe for all of your days. well, maybe not, but it looks like crap, doesnt fit, and is near impossible to get in. It is well worth the extra 40 bucks for an OEM seal. I learned that lesson well.

Larry Delor · #8 01-23-2006, 06:12 PM

I removed the front windshield out of a 123 to have as a spare just the other day.

After pulling out the aluminum trim, I peeled back the rubber that is on top of the glass and with a good pair of scissors cut a slit perpendicular to the rubber. Next I grabbed a hold of one of the newly made sides, and started to pull. This worked well for the most part...every now and then it would tear completely, so I had to get a fresh grip. Once that strip was removed, it was just a matter of gentle pushing from the inside, and the window popped right out.

It was thinner and lighter than I imagined it would be.

I have put off installing it in my daily driver, as I don't know anything about the adhesive they use(d).

rs899 · #9 01-24-2006, 07:05 AM

I am going to be doing a lot of this in the next few months. Both my newly-acquired '77 240D and 300SD need both front and rear seals. I have done a rear on a W123 and it wasn't fun. (And several other marques).

Mismost- great general writeup. I made a nylon push stick by cutting off the end of an old toothbrush and reshaping the stump.

LarryD- I hope you didn't flex the aluminum trim. If you bend it the least little bit, it will never lie flat on the new seal.

The main reasons I "like" to do this myself are (1) I am cheap (2) I am stubborn (3) I don't like giving "professionals" the opportunity of failing, giving me the opportunity to buy a new piece of glass (4) What if there is rust in the window channel- are the pros going to give a rat's arse about it?

rhodes2010 · #10 03-23-2006, 01:38 AM

I was gettting a little water in my trunk (300D) on the right side, up
near the fuel tank. It was under and inside of the trunk seal, and the trunk seal
looks good, so I guessed rear window seal.
Rear window seal was dry and very cracked, little splits every 3 inches.
Found that I could even wiggle the window around reaching in from rear
door and holding the outside. Rear window was sorta loose.

So, cut away rear window seal from inside and easily pushed out window.
Looking at the metal on the car all the way around I cannot perceive where
it might have leaked. Rear deck, lip, speaker wells, all look good.
No rust or sign of water. Although that speaker well had a lot of dry silt
that made me suspicious.

So I am ready to reinstall rear window tomorrow night.
First I will put it in according to the instructions above from Mismost
(I studied the shop manual too) and after it is installed will add sealant
around the lip.

One More Thing: One of the defroster wires fell off, I will solder that on first.

79-240d-project · #11 03-23-2006, 12:13 PM

The rear window seal is pretty easy. Getting the window out is probably going to be the toughest part. Putting the rear window in is not that bad.

Try this thread:

http://www.peachparts.com/shopforum/showthread.php?t=109916

Diesel Giant · #12 03-23-2006, 03:52 PM

I just had a new front windshield and seal installed on the 82 coupe, and it took too experienced glass installers, 2 hours to do. I thought it would be easy, but after seeing how much they struggled, I would let the pro's do it.

rs899 · #13 03-24-2006, 08:14 AM

The glass is really not that bad. My wife and I (and 5 yead old kid)did the front and rear of the latest 240D a few weekends ago with little problem. Took about an hour each piece. We even used the dreaded non-OEM seal and it went well. The hardest part was cleaning out the front windshield channel of old rubber. We have done 3 of these now (and 3 other lesser marques) and they get easier each time. You just have to suck up your courage and DO one. Next- on to the W116.

signalredcoupe · #14 03-24-2006, 08:25 AM

I'm having the front windshield replaced on my coupe through insurance. Does the glass guy provide the seal? Somebody told me this, but I can't believe thay would throw in a $100 seal for nothing (Florida - free glass) Paul

_______________________
'84 300CD 290,000

babymog · #15 03-24-2006, 09:50 AM

I've done the lubricated-rope thing several times, (parachute cord works great), works well. Make sure the window is lined up very well before you complete the install, and urethene is messy but necessary for sealant IMO if you are re-using an old seal (and only then if it is still soft and pliable).

I found a perfect OE windshield last summer for my vintage quattro, decided to have it professionally installed, ... they cracked it. Next time I'll do it myself. They later told me that "used windshields sometimes have hidden problems and crack easily", ... don't know if that's true but no sense arguing.

I have a flawless original windshield for my 190, will try installing it next week, certainly more of a pain with the sealant-type installation. I'm not sure however that a professional would get the original wire-in-tape installation kit to install it, and the last time I had a windshield replaced in my Land-Rover it took three tries to get it to stop leaking, ... I hate windshields.

- Jeff Miller
190DT in Holland, MI