1974 build predates wider median
That means the springs, the rollers, and sometimes the whole door are original to a build year that predates almost everything else in the wider service area, where the median sits closer to 1984. Original torsion springs from the mid-70s are past their rated cycle count by a wide margin - most spring steel is good for somewhere around 10,000 cycles, and a door opened twice a day for fifty years has long since burned through that.