111 Window Mechanism Restoration

[Sandy Lenhart]

I have a '71 280se 3.5 cab in excellent (mostly original) condition. One area that could use attention and where I could use a few suggestions is the front window action. There are 2 issues in both front windows that I am not sure how to tackle but that I am sure others have already figured out.

The first is that the window action up and own is slow and labored. I have had the door panels off and looked inside. Seems like (a) there is too much friction in the window tracks and (b) the regulator mechanism itself is shifting around due to worn nylon and rubber bushings. The motors still seem strong, but I can't imagine the extra resistance is good for their long-term survival.

The second is that the window seems to want to tilt several degrees backwards at the very top of its vertical travel so that the trailing edge of the front window is no longer parallel to the leading edge of the rear window. Everything is OK, but slow, at the bottom; I get the 90% of the tilt in the final inch or so of travel.

In regard to the first problem, I do have the little window repair kit. Do I need to remove the entire regulator and motor mechanism to repair it? Are there any tricks I should know? Also do I need to replace the felt strips in the window frame to get less friction? If so, how do I do this? Is there anything else I can do?

In regard to the second problem, it may be caused by the loose regulator, but I am just not sure. I seem to see the tilt on unrestored examples, but not on the restored ones. Does anyone have any other ideas?

If anyone in this esteemed group could share some knowledge in this area, I would greatly appreciate it. Even better, if anyone near Sarasota, Fl, has worked on the problem, that would be a dream come true.

Thanks, Sandy

[Tony H]

Hi Sandy,
I have been (and am) there. I think the tilting is caused by the shorter rear track letting the window move near the end of it's travel. I think new felt might tighten the movement up. I have the same issues on mine but it's all dissasembled so I have not seen the results yet. My regulator mechanism mounting bushings are also NG but the dealer could not seem to figure out what they are. I just subscribed to EPC so I will try to figure it out. There is a lot of adjustment in the vertical tracks to put the window in the correct verticle location relative to the rear window and roof. If improperly adjusted it can cause extra drag from the front window rubbing with excessive pressure on the rear window or tweaking the window when the door is closed. There is a lot of trial and error in adjusting. I had mine adjusted so the window just barely contacted the seal of the rear window and it seemed to help a lot. There was no wind noise when driven. I have talked to several coupe owners and they all seem to have slow windows. It's too bad such a fine car has that shortcoming when domestic cars of the same era have much better power windows. Anyway there's a lot more that I haven't mentioned here but hopefully this will help. Let me know if there's anything else.
Also I think you can install the nylon bushing kit without removing the window or regulator but you may end up taking it all apart anyway during replacement of other items.
Tony

[Sandy Lenhart]

Hi Tony and thanks for comments,

A couple of points from my side:

First, it is good (not good but comforting) to know that others are struggling. I was surprised not to find any previous threads in the forum on this issue.

Second, what is EPC, to which you subscribed?

Also, I am sure you are right that the front window tilts back as it rises in part because of the absence of a rear window frame above the door. But I also think the regulator contributes because, as the window rises, the regulator arm slides forward on the horizontal metal bar that supports the window. Once the regulator arm gets forward of midpoint, it wants to tilt the window rearward. But what actually allows the window to tilt in my car is the play in the bushings. The only thing I can think of that will control this is to eliminate the play by replacing the worn bushings. (PS: I also think the system is designed tight to bind the windows in place, meaning that more torque, and hence slower gearing, is required to operate it.)

I also know I have to fool with the frame adjustment. I tried once and got too much of a lean in. I need to readjust it more like the way you did yours. That will also take some resistance off the mechanism.

BTW, how do you replace the felt in the channels? Do you have to take anything besides the glass out? Can you get new felt at a dealer?

Thanks again, Sandy

[Tony H]

Hi Sandy,
Sorry it took so long for me to reply. "EPC" is a subscription service that gives access to MB's parts database. It's very similat to what the dealer uses to look up parts. Here's the link:

http://epc.startekinfo.com/epc/

The dealer has the channel and window scraper. They show a different part number for the front channel and the rear channel. Not sure what the difference is as I have not purchased mine yet. You will need to pretty much disassemble your doors to install it correctly. I have not got to putting my doors back to gether as my project is rather large in scope. I also had a idea of installing limit switches on the windows to stop them in the proper place before the motor jams them against the stops. Might be awhile before I get to it.
Part of what makes the window tilt is when the front of the window stops at the top of the frame and the back of the window is pushed down. I found the upper stop was misadjusted allowing the window to close too far.
Drop me a PM and let me know how it goes.
Tony