Tilt-Out Side Window Adhesion Failure

[audisnapr]

Several months ago I walked out to the van to see the tilt-out glass, intact, but on the ground. I leave the two tilt-out windows open year-round to make sure I get airflow through the van so when the adhesion on the passenger tilt-out glass finally gave out, the glass slid off its track and fell to the ground.

I've tried three times to rebond the glass to its seat on the window assembly but nothing has worked. I've used two different types of black silicone and one gasket maker - none of which have held. The shape of the glass does not exactly match the seat that it sits in so it wants to pull away - this of course is not helping during the curing process. I've had to come up with some creative ways to keep the pressure on the glass and even after letting it cure for weeks, it still won't hold.

For now, Gorilla tape is doing the job but want to get this resolved correctly.

Does anyone know what the correct adhesive is for this application?