Removal of rear windshield on W126 - PeachParts Mercedes-Benz Forum

pexcellence · #1 11-01-2004, 04:34 PM

I am trying to repair a rust condition on my 86 420sel on the bottom of the rear windshield. How hard a job is this to remove the rear windshield? Do I have to replace the seal after the windshield is removed? I search the archive here, but no step by step instruction. Don't want to break the glass in the process. Last time I check, it was about a $1000 for it.

Thanks,
John

Hatterasguy · #2 11-01-2004, 04:52 PM

Yes you will need a new gasket it is about $80-$90 from the dealer. As for removing it I have yet to do this same repair on mine, I am waiting for winter break. But my dad has removed one from my parts car and he said it was simple. I know you need to pull down the interor panals to disconnect the connections for the heater. I think after that you can just push the rear window out but I am not 100% sure.

bhatt · #3 11-01-2004, 05:47 PM

I just dropped by the local MB dealer bodyshop to get a quote on fixing rust in the same spot on my W126.

The bodyshop manager has been there for years and knows his stuff. He has painted my car before and knew exactly where to look for rust spots on W126's, etc.

He insists the gasket can be reused. I thought that was kind of weird, but he said they always reuse them unless there are visible cracks or if they are rotted.

I was quoted 3hrs to remove & reinstall the back glass, so that should give you an idea. He said the rear interior panels (as hatterasguy pointed out) need to be removed. Both apparently need to be removed since the heated element has two connectors, not just one.

He said to be VERY careful while the glass is out.. its quite fragile unless installed and very easy to crack.

You might want to have a glass shop quote you on the remove/reinstall and do the rest of the work yourself.

I was quoted C$180 to remove/reinstall (using existing gasket) and C$200-250 to sand all of the rust, treat it properly, then repaint both rusty areas. Mine is bubbling out from under the gasket and now reaches about 1/2" away from the gasket edge. The rust spot is about 3" wide (the visible part anyway.. I'm sure there is more!)

I figured for the C$500 it wasn't worth it trying to screw with the glass, risk breaking it, sand & repaint rust, etc. My point is you may want to check with an MB dealer or VERY good shop.. it may not be worth your time to mess with it.

Hope this helps!

Neal

Hatterasguy · #4 11-01-2004, 06:57 PM

I would replace any gasket that is over 5 years old. I don't want any leaks or to have to re do the job.

My local body shop wanted $800 to pull the glass and replace the chrome trim and rear seal. But they said to fix the rust they would have to cut it out and weld in new metal. Their a resto shop, and their right that is the proper way to fix it but I don't have $3k now to spend on that. So I will just grind it down and paint it for now.

backstage1 · #5 11-02-2004, 12:26 AM

Quote:

Originally Posted by Hatterasguy

I would replace any gasket that is over 5 years old. I don't want any leaks or to have to re do the job.

My local body shop wanted $800 to pull the glass and replace the chrome trim and rear seal. But they said to fix the rust they would have to cut it out and weld in new metal. Their a resto shop, and their right that is the proper way to fix it but I don't have $3k now to spend on that. So I will just grind it down and paint it for now.

I looked at an 89 560SEL that had a 2" long spot at the base of the window. The car being sold by an MB Indy and they called the shop they use. They would charge about $650 to do the job. I think they said they'd actually have a glass guy come in to pull and replace the glass and that definitely included a new gasket.

~Bill

pexcellence · #6 11-02-2004, 12:49 PM

Locally, a body shop quote me $200 for the job, reusing the seal. But he said he will grind down the metal and use fiberglass sheet to fill in. He did my front windshield, replacing it with a new one (was badly cracked), sand down all the rust, paint new primer and reseal it due to water leakage for $299. I guess I can't complain.

John

donbryce · #7 11-02-2004, 01:44 PM

I had the rear window replaced on my '85 380SE by a local auto glass specialty shop (Standard Auto Glass, Canadian, don't know if they are in the U.S. too). I dropped the car off after the glass arrived and they had it installed in under 2 hours.
They did call to let me know about a rust spot hidden by the seal on the lower lip, which I went over and treated myself with some steel wool and metal prep. They applied a coat of glass primer, re-used the rubber seal after cleaning it up, and the whole job, including glass, was about $500.00 CDN.
I brought the shop manual over to provide details of interior panel removal, glass removal and install procedure, etc. The guy told me after that he didn't even have to take out the package shelf, just pulled back the side panel to reveal the heater wire connection and that was that, no leaks at all over the summer (done in April).
There's a HUGE difference in the price of OEM glass and aftermarket. The only visible difference is the heater wires. The MB version had a large number of fine wires running vertically. The glass from India had thicker wires running horizontally. I know some have posted here that the fit is not always as good with the non-OEM either, but mine seems OK. The price differential was about $900.00+, so I'm living quite contently with the latter design, which is fine for a car that never sees winter here anyway.

Dee8go · #8 01-14-2009, 03:47 PM

Quote:

Originally Posted by Hatterasguy

I would replace any gasket that is over 5 years old. I don't want any leaks or to have to re do the job.

My local body shop wanted $800 to pull the glass and replace the chrome trim and rear seal. But they said to fix the rust they would have to cut it out and weld in new metal. Their a resto shop, and their right that is the proper way to fix it but I don't have $3k now to spend on that. So I will just grind it down and paint it for now.

Why would that be? Does the rust penetrate into the metal to the point that you can't grind it all off without grinding a hole into the body? Besides that, aren't welds pretty susceptible to rust themselves?

Hatterasguy · #9 01-14-2009, 05:58 PM

Well usualy their is no metal left. The right way to fix bad rust is to cut it away. If you grind it, it does come back...or you run out of metal to grind.

I just sent Brian the part number for the metal piece below the rear windsheild on the W126. They are cheap like $75, and when I bought mine Mercedes only had like half a dozen left in stock, period. So if you plan on having W126's for awhile it wouldn't be a bad idea to get one or two just in case.

I figure if I never use it, I'll sell it for $200 when Mercedes doesn't have them anymore.

Hatterasguy · #10 01-25-2006, 10:49 AM

You need to cut the gasket in order to pull the rear window. So re using the gasket is just not possible.

Body shop labor rates in my area range from $65-$100 an hour. Since they need to pull some interior panals to disconnect the heater connections, and remove that pita trim, I'd figure 3-4 hours labor for any shop.

Rust is another tricky area, any good body shop will want to cut it out and weld in new metal. The shop I took it do does awsome work and flat out refused to do it any other way. They are a very high quality resto shop that doesn't mess around or put their name on anything sub par.

The grinding it down and painting it just buys you time. Since I did this job last year I noticed rust poping up again.

So this year when I paint my car I'll pull the rear window again and see what I find.

One option I am considering is cutting that sill section out of another car and welding it into mine. I am pissed because my 420 parts car I sent out to the junker was rust free under the window. I should have cut it out I wasn't thinking!!

TX76513 · #11 01-25-2006, 10:55 AM

Hatty, I didn't cut my gasket

to remove it. Take your time you can get it out. It will take more time to get the gasket seperated from the body than it will to re-install everything (once you figure out how to re-install)

MS Fowler · #12 01-25-2006, 04:50 PM

I agree, cutting of the gasket MAY not be necesary. If its old and brittle, of course you will have to cut it, but you wouldn't even want to reuse one in that condition.
I needed to replace the glass in my '82 300SD that I had removed for painting. I cut the gasket on that one so I wouldn't distort the trim. It distorted anyway, and would not go in. I ended up cracking the glass trying to make it all fit, including a new seal.
Then I went to my local auto junk yard. their fixed preice on rear glass is $40 if you remove it. Heck, I wanted to remove it myself. I found a later W126 with a good seal; no crack, and quite supple. After removing the trim and unscrewing the heater connections, ran a flat-bladded screwdriver all around the inner edge of the seal to break the bond. Then I pried one of the upper corners over the lip in the opening, and worked the edge across the top of the glass, prying a little and pushing a little, Once I had a good start, I put my feet on the glass, right at the edge, and pushed while reaching past my feet to pull the edge of the seal over the lip. After a few minutes, it just sort of all unzipped. I ended up with a good glass, with the seal and trim intact. I reinstalled it the same way, never taking the trim out of its channel.
I reinstalles easily using a rope in the channel for the body pinch weld. Keep it well lubed. I also (gently) laid an 80 lb bag of sand on the lower edge on the trunk side to hold it in place while I zipped out the rope.

Dee8go · #13 01-08-2009, 03:46 PM

Did you reuse your old glass? I've been told by a lot of people that it's very hard to get the old out without breaking it. So, I didn't want to proceed until I was sure I could get another piece in the event that it DID break.

Hatterasguy · #14 01-08-2009, 07:23 PM

I'd go to a junk yard to get the rear glass, I got mine from my 420SEL parts car.

It could break, if your carefull it probably won't though.

Dee8go · #15 01-09-2009, 08:53 AM

The defroster would really be nice considering where I live. I don't use this as my primary car, though, so I could probably live without it. If I could find glass without the defroster for $200-300, as opposed to a window WITH it for almost $2000, I would definitely learn to live without it.