While it appears to be well worn and sloppy, none of that moves when in the tracks. It possibly needs that amount of movement for channels that are not part of the doors or parallel. The rollers don't even roll, it's all very firm. You'll also need the door trim on to support glass not touching the outer seals. Also not the fuzzy guides on the window tracks are often worn out and forgotten, as in, not even known about by many. A tiny bit here and there all adds up.