I'm trying to make my vent window close but it is being obstructed by what appears to be a newer gasket (really stiff uncracked rubber). I took the entire assembly apart to lube the worm-shaft mechanism and get a better grasp on the task at hand. The problem seems to be that the gasket is too short at the bottom. It doesn't want to stretch from 90 degree corner to 60 degree corner. Thus it keeps the vent window slightly ajar-noisy at speed. Is this typical? Is there some "magic" way to stretch that gasket so it will fit? TIA