Rear window problem

[bbig119]

The other day I noticed the rear passenger side window would tilt forward on its way up. It still works but makes a thumpy noise when it shuts.

I searched the forums and it seems window problems are common on the e34, and the regulators go frequently. I've seen a number of posts by Jeff telling people to lube/replace the rails that support the window. I plan to check this out, but what I wasn't able to fush out from older threads was what is whether this is most likely just a simple rail/slide support issue or if I'm going to have find a small stash of cash to pay for a new regulator, or even more.

[gale]

My former e28 used to do that. You'll prolly have to take the door panel off to find what's wrong. The e34 is a different design but what happened with mine is the bottom edge of the glass detached from the metal clip that it's bonded to. I was able to kludge it back together with a piece of bicycle innertube and JB Weld and ran a bead of aquarium grade RTV along the whole bottom edge where it attached to the metal strip. I ended up repairing all 4 windows in a similar fashion by the time I was done with it & they lasted for several years right up to when I sold it. Cheaper than buying a new window and easier than dismantling the frame rails to get the window in & out.