On a 1988-built house, the sound usually starts as a single bad roller clicking near the top or bottom of travel, then turns into a grind that happens on every cycle as the flat spot wears further into the wheel. Houses in this part of the service area sit in a mild coastal climate without hard freezes, so you're not getting the ice-cracking failures some regions see - here it's slow wear from humidity and salt air working into steel rollers over thirty-plus years, plus the door simply getting used. If you're hearing a rhythmic thump that matches the roller count rather than a single sharp bang, that's rollers, not a spring, and it's the cheaper call to make.