Let me take shot at this, I think I understand as a had a similar problem. I'll try to recall from my memory what I did and why.

My 760's sunroof though would slide to the rear (powered). When I wanted to close the sunroof, it would cock to one side and then jam. I had to use my right hand pressing on the underside and add forward pressure to keep that side from jamming up. I learned that there was a small tab on the right side track, track attached to the roof, that was broken off. I went to a junk yard and removed a track assembly.

First I put the sunroof in the tilt position. Then, I believe that I disconnected the headliner from the sunroof. This is done outside the car and just behind the sunroof. A clamp type spring on each side of the sunroof must be released. This allowed me to slide the headliner to the rear, out of the way. This exposed the screws that attached the sunroom to its support mechanism. There are a set of two screws up front on each side and a set of two screws on each side towards the rear. These screws also a adjustable for sunroof proper position when in the closed position.

So once the sunroof "roof" can be removed, the slide mechanism on the "roof" and on the car is exposed for inspection and replacement if necessary.

I hope this makes sense and I hope I have understood your problem. I also took this oppotunity to replace the furry gasket that attaches to the periphery to the "roof". I also recaulked all possible places that would be a source of leaks. I also reamed out the drain holes to make sure that they were clear to allow water to drain quickly.

Mikke
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'83 245 GLT, '92 245DL, '90 760 GLT