I am helping a friend adjust the driver's side window on his 67 Ranchero. It stops upwards travel about 1/4" from being all the way into the window channel, leading to air and rain leaks. I pulled the interior door panel, but cannot see a place to adjust the upwards travel. Is there an adjustment for this? Or am I possibly just looking at the window channel being too tight? (I don't really think this is the issue.) Thanks.