Some adjustment screws sit behind caps or are obstructed by surrounding finishes. Photograph what is safely visible without dismantling the door. Blocked access can alter the work plan; a damaged adjuster should not be forced to compensate for a worn or incompatible roller.
Roller housings can differ even where doors look alike. Provide the door maker or part reference if known and photograph accessible identification. Do not remove a heavy panel just to obtain a measurement; safe access to the assembly must be planned first.
A panel can have more than one roller assembly, and the condition of each matters. Discuss whether compatible assemblies need replacing together. Replacing only an obvious damaged wheel may leave an uneven panel if the other support is worn or cannot be adjusted correctly.
Replace accessible compatible roller assemblies on an accepted panel, set the height and check ordinary travel and stops. Scope limits: Ordinary non-powered safely handled panels only. No heavy specialist lifting, glazing work, powered operators, structural changes or access-control integration.