114 Coupe Window Problems
 

I am trying to get my 280C to be (more) watertight, and quieter at speed, like less wind noise.

So a while ago, I replaced the weatherstrip along the top of the windows. but it did not do a lot of good because the window does not fit correctly along the top. This is on the driver's side.

What seems to be happening is that the rear of the window is about 1/4" below the front when the window is all the way up. The window seems OK until it is about 2/3 of the way up. Then the rear starts to sag, the window sort of jumps, and the front begins to come out of the channel near the top. The window also seems to be very hard to move up and down by hand.

There is limited front and rear adjustment at the front channel as well as lateral adjustment. The rear channel is completely in the door and has lateral adjustment only. The weatherstrip/lining in the front channel is OK, but the rear's is completely gone. I will try to track down the parts to fix this, but I don't think it is the whole problem.

It is almost like the curves of the window and the channels don't match.

I did install the lifter repair kits, which are shown in the parts manual. They helped the sag, but did not fix it completely.

Has anyone had this problem and fixed it, or been through the process of putting the window, lift and channels in a replacement door?

TIA

Re: 114 Coupe Window Problems
 

I've got no idea what those kits would contain, however......

I had a problem that got increasingly worse with a window. The "bolt" that goes through the spring that helps the raising arm was on it's way out, adding weird angles into the equation.

The window exhibited systems similar to yours, the window wouldn't quite close, then one day the "bolt" gave in, and I had a non-raisable window.

Upholstery off, replaced "bolt" with a bolt (discarding the spring in the process I believe).

Worked fine since.

Now that you mention it, my '72 250C drivers' power window does the same thing. I haven't checked mine out yet as it mostly stays in the garage. Typically, frameless coupe windows have other alignment provisions to compensate for the limited window channels. Is there any 'angle' adjustment possible at the window regulator? Are there any adjustable 'stops' built into the window glass or door slot to limit the glass coming up too high?

Happy Motoring, Mark

280C window alignment
 

I have exactly the same problem with my 280C (nice description of your problem). Yesterday I pulled the regulator and motor and found no aligment issues with either. The regulator mounts, on the other hand, were another story. They use a sandwiched rubber/zinc mount, and the rubber had deterioriated. Also, previously, someone had poorly 'repaired' the mounts using a poor choice of hardware, and left some of the rubber out. This allowed the regulator to move slightly, which was visible watching the ends of the four mounting bolts and nuts. I am currently trying to find out of MBZ has repair kits for these mounts.

There are several adjustments I found during the procedure which I didn't notice before. There are two (8mm socket) bolts at the top of the door which hold the upper stops. These bolts are accessible through a hole in the inner door skin, and allow for adjustment of the upper stops. Also, the parallel linkage that attaches to the bottom of the window has a pitch adjustment on the lower end. Look at the outside of the arms for a nut (away from the passenger compartment, inside the door, i.e., hidden). Loosening this nut allows the linkage arm to swivel and adjusts the pitch of the bottom of the window.

The lower glides that attach the regulator to the window were also shot, repair kits are available at your dealer for $6.25 each (2 per window), p/n 123-720-0114. I tried this first, and when it didn't work, the next step was to pull the guts out of the door.

By the way, the wire to the motor was frayed to three or four strands where it exits the motor housing, apparently the result of previous ranting during installation. Repairing this should stop the fuse-blow problem I was having.

I did both glides - what a pain to get the clip on!

The lining for the window channel at the rear of the door is still available - and in the US (Orlando) no less. I ordered it and it should be here in a couple of days.

Since mine was completely gone at the bottom, I am hopeful that this new piece will provide additional stability to the back of the window as it rises and help keep the front edge in its channel.

Window Adjustment
 

I spent a lot of time fiddling with the window after I replaced the "chase" at the rear. The window is not exactly gliding up and down, but I did get it to go up to the correct position and it is almost straight.

The key to getting it straight are the three adjustments, which I have tried to identiify in the picture.

1a - rear stop/adjustment
1b - rear tab

2a - center stop
2b - center tab/adjustment

3a - front stop/adjustment
3b - front tab.

In the rear and front adjustments, the tab on the regulator moves up against the stop, and the stops are adjustable up and down with a 10mm socket.

In the center adjustment, there is a ledge built in to the inside of the panel, and the tab bolted to the regulator moves up against it. The tab is adjustable, again with a 10 mm socket.

I am not making this up.

My procedure was to adjust the height with the center adjuster, then get the angle right with the front and rear stops. It seems like the window sags a bit to the back coming up, but it hits the front stop, and the back then comes up against the rear one.

I also need to find a better regulator - I think that's where my creaking and chattering is coming from.