Brandon, most common problem with the window mechanism is lack of lubrication on the sliding block in the bottom channel on the glass itself. The other item that will cause problems is the rubber channel the glass rides in. If they get to worn the glass tilts as it tries to slide up, down will usually work reasonably well.
There are adjustments on the lower portion of the rear channel, but the door panel has to be removed to get to them. This is inside Darth's left front door, disregard the extra wiring, adjustment/attaching bolts are labeled.
Bill AKA "LOBO"
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"Getting old is inevitable, growing up is optional"
Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator
Wife's 2011 Flex Limited
Daily Driver 2009 Flex Limited with factory tow package
Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413