Alot of times that has to do with the inside front & back channels. Not the tracks themselves but the bottoms of the window frame (kindof a rubber fuzz lined gasket).
If the window isnt where it wants to be it slows considerably. Never had a motor that got weak, mine were good or bad.
Drive for a couple of days without the door panel cause as SOON as you button it up things start going bad again.
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Steve 96BBB 28K 3.42 Bolt-ons
95BBB 100K 3.73 383 New DD...already
broke fixt the 4L60E twice
95 Black WB4 Hole...ee...grail
96 Black WB4 No holes in this
95BBB 189K 3.08 Old DD Stolen...by Matt.
Whine..eee...Silver LS6