It doesn't really have anything to do with old vrs. new. They haven't changed, it's just the luck of the draw...
so, why is it that some work and some don't? shouldn't they all have the same internal parts?
They say a good mechanic only needs 2 tools - WD40 & Duct tape. If it moves, and its not supposed to, duct tape. If it doesn't move, and its supposed to, WD40.