From the early 70s, through the early 2000s, Ford has used
this same basic design Power Window Motors. They have a intermediate
gear set that is made of plastic parts. There are 3 round spacers in
the gears that deterate over time, and cause the window to not work
properly, and just chatter.
Remove these parts, and clean out all the small pieces
Apply some grease to the inside parts.
Place (3) 7/16 hex nuts as shown, then some grease.
Insert the center gear
Install the gear cover back on. Spray all of
the parts that the window moves in, or on
with silicone
Follow this video on how to remove, and reinstall
the window motor.