Lubricant drying in heat
After two-plus decades of severe summer heat - and Coolidge sees the same brutal stretch of 100-plus days as the rest of this region - the lubricant in those older openers dries out faster, and torsion springs lose tension sooner than manufacturers spec for milder climates. What you notice first is usually the opener straining harder than it used to, or a door that reverses partway up for no clear reason.
