We run this truck out of Gallatin, about 14 miles from Goodlettsville, so we're not sitting on standby around the corner - we schedule the trip and bring the parts likely to match what a 1990-era door needs, including gear kits and standard torsion springs sized for that period's door weights. If a job turns out to need a part we didn't bring, that's an honest limitation of working a route rather than a storefront on your street: we tell you up front and come back with it rather than guessing.
With 7,531 households in Goodlettsville and most of that stock dating to the same build era, we see the same handful of failure patterns repeat house to house - which is useful, because it means a lot of these repairs are diagnosable from the symptom alone before we even open the opener housing. We check spring weight against door weight, test the board under load rather than just visually, and don't replace what's still doing its job.