Window regulator movement

Hello everyone!

I have recently changed the window regulator system (right side-passenger) of my 3000GT VR4 '93 American model (MK1) and still do not work smoothly. It seems that the rubber makes too much pressure or friction and the glass has trouble for moving, especially upwards. I have checked that the inner rubber-water strip still has felt and it seems to be quite good, it still has and it seems soft. However, when I raise the window, when the glass is already 75 percent from the top, the rubber, from the part closest to the mirror, begins to bend upwards, the glass drags it. Also, when I lower the glass, just when it leaves the area of ​​the triangle that is in the front of the door, glass makes a rough movement . I have tried releasing the screws pressure on the regulator bracket a little to see if the glass get a natural/better position but it did not go well. It is difficult to climb. The rubber bands (water strips) I think are well placed, with the staples in the holes and good position. Is there anything I can do to fix this? Should we change the rubbers?
Thank you!!

Hi Oscar
The window mechanism is quite basic and yet if any component of the system is loose, faulty, warn or mis-alined, the whole thing goes wrong. A number of people have asked for a video on how to align the window and I have tried to do one a number of times but failed every time because the problem has not been alignment but a fault. You can’t use the manual because it relies on all of the parts being perfect. For this reason, I will be doing a video, but it will be a full strip down and service of the window system. This is the only way I can show how to sort this and many other problems with the system. I will try to do this soon but it is quite a long video so I am just trying to find the time to fit it in.


Hello Joe,

Thanks for your reply, it will be great to see that video :slight_smile:

As you say, it seems that all the components have to be very good or perfect for smooth movement. Today I have lubricated the rubber with silicone lubricant and I have noticed quite an improvement. For now, I leave it at that. It works quite well but it is not perfect. I am a bit picky with this things :sweat_smile:

Hi Oscar

Is the rubber on your weatherstripes in good condition? With time it loses its flexibility becoming more like hard plastic and starts pressing onto the window glass when you move it up and down. And it cant be adjusted. The rubber needs to be soft and flexi. I had the same issue. Replacing the stripes has addressed the problem.

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Hi Vince_GTO,

It seems to me that water strips are not too bad, but I am not sure, I have no others to compare. I suppose they will be worn as I added silicone lubricant and it improved, so it is probably something with unsuitable friction with the glass (worn rubber or loss of properties), but I am not sure.

Just roll down the window and touch by hand the rubber edge. It should be super flexi - bending in and out w/o effort. The fact that lubing ait has helped hints that the issue is indeed witht that.

Me too, until I got new stripes I had no idea how bad the old ones were. The rubber has become a hard plastic.

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Is it possible to buy outside and inside rubber strip for the door? I have seen outside one.

I uploaded a video of the window movement after replacing the regulator and lubricating the rubber. Check this drive link:

What is your opinion? Because I don’t know how it works when it is new. Maybe it is not too bad…


Well buddy, think yours is as good as it gets!

From the video I see your outer stripe’s rubber flexes so all good in the department.

I wouldn’t mess with it any further.

But… let’s see what is gonna be in Joe’s video on that subject, maybe there are some alignments that are not widely known.

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Thanks for your answers and help. Yes, now I will leave it like that and if later with the video of Joe, for example, I see that I can improve it, I will try. At least it can be opened and closed decently :slight_smile:

Mine started doing the exact same thing after replacing the strips. Also I noticed on each window a tar like substance on part of the window. It worked fine before I put new weather strips. I haven’t found a solution the rubber is fine it seems since it is new

After adding new strips mine began doing the same thing The rubber seems fine but maybe it is “harder” I don’t know what it is but it started after adding the new strips for me.


I applied silicone oil to weather strip and the windows moves better. First the glass get a bit dirty because the oil but after some time the rubber/felt seems to absorb the oil and it is ok.
The ‘triangle’ at the front of the door needed a lot of lubricant. My weather strips are not new, I just replaced the window regulator.