Late-1990s build prevalence
That matters for the kind of maintenance call we get. A door installed in the late 1990s typically came with a torsion spring setup rather than the older side-mounted extension springs still common on 1960s and '70s stock nearby. Torsion systems are more forgiving over time, but the openers paired with them back then were usually chain-drive units with worn nylon gears by now, and steel rollers that have long since lost their coating.
