coupe rear window fix, anyone done this????

[lutzTD]

it seems from observation not many coupe rear windows work. I have seen a lot of posts for regulators so I figured mine was on borrowed time. Since the air isnt particularly strong on this car I roll down all of the windows. 2 days ago the inevitable pop and the passenger side rear window drops down free. I was able to duct tape it up for a coupke days, confident I would not exceed the 200mph rating of the tape .
today I pulled off the cover and it looks like an easy fix. the pin that attaches the regulator popped off. I pulled the bottom cover plate off and gravity had taken care of the pin, straight down from the joint and stuck in a glob of lithium grease. I put the pin back on and the clip and ran it up again. then a cycled it a few times and pop, the clip comes off again. second time I had the window in a different position where it was easier to put the pin in with the little arm below the big arm. this time, to my amazement, the window went all the way down to the bottom of the opening. . since I never had a coupe before I thought half way was the complete travel. so I cycled and cycled it many many times and finally at half way down the little bar passed throught the bottom to the top, on the return down it jammed half way down. each of these cycles the little clip rubbed the big arm so I assume thats what finally causes it to let go. the way this mechanism works is that the tracks rock forward and back as the window goes up and down. this allows the window to follow a circular path and allows the window to go all the way past an area it could not in a stright path. when it flipped the little arm, the back and forth was not working right and it allowed enough movement for the little arm to turn all the way through.
so I cannot figure out how to insure the back and forth travel of the tracks. it seems dependant on the side load induced by the little arm as it gets closer to the big arm.
my solution is to drill a hole in the long arm and put a screw and nut that wont allow the little arm to pass behind the big arm. Has anyone ever done this? if so did it cause any issues? I looked at the motion of the arms and it looks like the stop would force the front to back track movement if it becomes stubborn. screw driver shows the point I would put the stop bolt.

[Jimmy Joe]

geez, I could never figure out how to get the darn plastic cover off in the first place...did you mess yours up?

[lutzTD]

Originally Posted by Jimmy Joe

geez, I could never figure out how to get the darn plastic cover off in the first place...did you mess yours up?

my car was a parts car for the preious owner appearently. every single peice inside has been removed and haphazardly replaced. mine was sitting loose once I pulled off the corner piece between the side window and the rear window.

[Jimmy Joe]

Well, you sure got a pretty one. nice rims too...

[lutzTD]

Originally Posted by Jimmy Joe

Well, you sure got a pretty one. nice rims too...

thanxs, its rust free but theres not one good peice of trim on the whole car. but hey, restoration is not a destination its a journey

[Johnhef]

on my 82 CD i somewhat fixed my non worrking rear windows by repairing/bending the bent regulators but even after getting them to as close to 100% as I could, they would still bind halfway down, you had to tap the up switch for a second then press down again and they would go all the way down.

One way to skip all this would be to just buy new regulators, expensive, but I recall someone saying theyve been redesigned.

[lutzTD]

Originally Posted by Johnhef

on my 82 CD i somewhat fixed my non worrking rear windows by repairing/bending the bent regulators but even after getting them to as close to 100% as I could, they would still bind halfway down, you had to tap the up switch for a second then press down again and they would go all the way down.

One way to skip all this would be to just buy new regulators, expensive, but I recall someone saying theyve been redesigned.

Im going to add the screw and see what happens. worst case I still need a new regulator. it looks like if there is a stop to push the tracks in the front to back motion it wont be able to bind. I cycled mine up and down 50 times and it works perfectly as long as the little arm stays below the big arm. there is a hole in the regulator that kinda lines up with what looks like a stop pad on the window pin tab. i wonder if there is an original MB piece that goes there that could have deteriorated and fallen off. has anyone seen a brand new regulator? rather than drilling a hole I may just bolt on a stop through that hole. will post progress, if it works Ill post the drawing of the piece I make.

[lowriderdog37]

Have you had a chance to mess with the regulator any more? Any luck? Can we get pics?

[my83300cd]

I've had both sides apart, and put in new regulators. I gotta say when I had em apart I compared the new/old regulators and could not tell if the old ones were twisted or wracked. With the new regulators in, my passenger side goes all the way down, if I rock the window a bit with the switch at a certain point. The Drivers side only goes halfway, but I know its because I messed up the orientation of the little arm at the end, and didnt have the time to redo it yet.

I think before you go for new regulators, I'd try replacing all of the white plastic guides and stop pads.

[79Mercy]

My rear windows go down but they bind up about halfway but will go all the way down if I play with the switch. I removed everything(pillar cover, seat bottom and back, chrome plate, cloth strip, screws and clips) but I couldn't figure out how to remove the panel. I tried to pry it up but I thought I was going to break it. How did ya'll get it out? Thanks

[NDP 2.6 190E]

Originally Posted by lutzTD

coupe rear window fix, anyone done this????

Yes. Both my rear windows were inop when I acquired the car. One was completely dead - turned out to be a disconnected wire on the motor brush. The other was a dodgy regulator that was binding.

The fix involves welding a small piece of steel to brace the regulator arm near to the pivot point that attaches to the window bracket. The pics show the welded area before I applied a coat of POR15). This is a known weak spot on these regulators - it bends at the slightest resistance and causes the window to jam, or the regulator arm to pop-off.

While your in there, be sure to check the motor brushes, clean and dress the commutator, clean & lube the gearbox, clean and lube the other moving parts.

Did this on both regulators and my rear windows have been trouble free ever since.

[Dionysius]

If mine fail I would be happy to just fix them permanently closed. Is there a good way to do this. These windows are seldom if ever used.

[RUN-EM]

Originally Posted by Dionysius

If mine fail I would be happy to just fix them permanently closed. Is there a good way to do this. These windows are seldom if ever used.

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the already mentioned duct tape. Then there is 5 minute epoxy by JB Weld. Er, th' welded joints method. Or pour sugar inna body cavity, leave it alone on the driveway fer a couple er days. The resultin' ant farm will purty well shut anythin up .

Regards

Run-Em

[Shark]

White lithium is not working well on my regulators.
What is the sticky grease the factory uses?
What do you use on these to prevent binding?

[JHZR2]

So can anybody comment if the "fix" shown just above is identical to the better design that will come from M-B?

Is the fix shown good enough to promise a working regulator? If so, I may try to find some good used ones and get someone to do a fix like that on them...