That'* a good question and a PITA problem from the sound of it. I don't know for sure, but it would seem to me that maybe the windshield guy removed them completely from the wiper motor drive shaft and then did not replace them correctly.
Since I've not had mine off, I would have to take a good look to see how those are mounted before I could make any good suggestions. However, it would seem to me that there is some sort of method to keep those in alignment. Likely either a splined mounting shaft or something similar.
Anyone out there know?
Mike: 1997 SE w/ 183K, aka White Horse
, Gutted Airbox w/K&N, drilled 180* t-stat, tint all around, clear corners w/SilverStars, "PONTIAC" light up tail, PEMs, NGK TR55s