We bring stock in both nylon and steel rollers on the truck, sized for the stem length typical on 2005-and-newer residential doors, and we check hinge wear while we're in there - a worn hinge eats a new roller just as fast as the old one. The door comes off the opener first, every time, so nothing's under power while hands are near the track.
We run the door by hand through a full open-close cycle before and after, listening for a dry roller versus a bent track versus a loose bracket - three different noises that sound alike to most homeowners. If the track itself is bowed, that's a separate repair, and we'll say so rather than sell you rollers that won't fix it.
Because we're driving the 6 miles out from Spokane Valley rather than working from a depot in town, we try to bundle anything else the door needs into the same trip - a loose hinge, a stretched cable, a sensor that's drifted - so you're not paying for a second visit for something we could've caught the first time.