separating RR window from regulator...

To move the Regulator by hand , you need to remove the windows electric motor 1st ( 3 Hexagonal screws) ,then you can slide it to any position you like , make sure all rivets are out .:thumbsup:

Look at the sides of the Window rail channel not the window regulators railings (where the window actually slides up & down at ), on the sides inside the rails you see some kind of inner protection that helps the glass slide up & down , sometimes that protection when it gets wet or disturbed ,specially down the bottom, it blocks the windows up/down movement .
By slightly adjusting the sides holding nuts /screws , that should fix that problem , Don't over adjust it .
Avoid any kind of oiling or grease on those railings , only ad some lube onto the regulators rails , not to much as in time dust will get to it .:thumbsup:

Once you found the adjustment screws , only slide the rail ( one at a time) by millimeters not centimeters , to loose & that results the window not perfectly closing on the top round curve ,which then results wind noise entering while driving , so annoying . If you adjust them to much like a tight fit ,the window will close slowly resulting with the windows electric motor eventually seizing to function .
Look at the inner railings glass protection on the far sides 1st ,clean them out of the dirt that has accumulated over the years .
My guess is that your problem is there for the windows to close either to slow & or brake the regulator so quickly .:thumbsup:

TIP: If you do adjust the side rails , make sure you mark the original position ,this way you wont go Nuts later if you need to revert back if all should fail .