HI! I dont know a whole lot about fixing your window but I do know that lubrication can be a big factor in it coming apart. Valco Cincinnati Consumer Products Inc. makes a spray lube called Gellube. I used it on the Quarter windows of my 69 Firebird and it has solved all problems. I used to have to help the windows as they would bind and be scary to operate.
I took everything apart and sprayed the Gellube on the entire mechanical assembly very liberally. It penetrates then sets up as a gell....The really neat thing is it is synthetic and it never dries up! I did my car almost 3 years ago and the windows still work like brand new! This stuff is designed for actual new engine assembly so window regulators are light work for it....Dont use WD40 as it will be gone by the time you reinstall the panels, as will most other lubes and the white lithium the factory used turns to a crusty dried out mess too. So check this stuff out....Part number 710XX756 at Valco 1-800-788-3865 ask for Margaret...Tell her flynbrian sent you.