As many people know, the exterior dew wiper has 2 fuzzy pads on it. These pads collect trash or wear out and damage the window.
I’ve had the doors apart a bunch recently and I’ve noticed the pads are very tight to the glass. This adds to the problem. The pads are pressing so hard they wear off the fuzz. They also trap small particles that scratch the glass.
The exterior fuzzy pads have an interior counter part. The interior pads can be adjusted. When you replace the exterior wipes adjust the interior pads so they are guiding the glass without pinching so hard the pads cause damage.
You need to remove the interior door skin to access the pad retaining bolts.
There is one 10mm retaining bolt for each of the 2 pads. The bolts are on the top of the door framing. Loosen these pads before installing the new exterior wipes. This also gives more room to remove the exterior wipe’s screws.
When you tighten the bolts push the pads up only enough to guide the glass and keep it from rattling. Don’t push them so tight they are clamping. This will allow fine particles to work past the exterior pad instead of being trapped between the glass and the pad’s metal guts. It will also avoid excess wear on the pads.
Those of you who have wipes that are in reasonable shape can keep them from collecting stuff the same way. Just move the inner pads away from the glass, clean the exterior pads, then push the pads up just snug to the glass and tighten the bolts. Don’t lean on them like Pontiac did at the factory.
In fact if the pads aren’t completely shot but the wipe is, cleaning and backing off the pads will help to prevent further scratching until you can replace the wipes. When you do this try to knock loose the dirt in the pads by gently running something dull, or maybe an old toothbrush over the pad front to back.
I did this on one of my crummy wipes and it’s helped quite a bit. I no longer hear it grinding as it goes down.