not really the linkage .. but the wiper arms are "press fit " onto the linkage post . The nut on top holds them down .
The linkage post is "splined"........... and the "press fit" of the arm , builds splines in the wiper arm and keeps the arm in place . if the arms are ever forzen to the windshield , or heavy mud situations ect .. the "splines" on the arm will strip , causing them to flop all over the place .. tightening the arm nut dosnt usually work because the hole has been enlarged ..
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