2024 Kenworth T680

Category, Truck. Mileage profile points to sustained highway duty cycles, with wear typically showing up in driveline joints, steer components, and aftertreatment service history more than in cab plastics. Serial 1XKYDP9X9RJ333955, stock 0636046, is best evaluated with a cold start, a loaded road test, and a full fault scan since ECM details are not provided. Powertrain verification needs a build sheet or dash readout, engine family, transmission model, and rear ratio are not listed. Diagnostic priority is an ECM and aftertreatment health check, active and inactive fault codes, parked regen history, soot load trends, and any derate events, followed by blow-by check, coolant pressure test, and crankcase ventilation inspection to establish current mechanical baseline. Frame rails and crossmembers should be checked for straightness, corrosion at fastener points, and any evidence of prior repairs. Fifth wheel wear points include top plate scoring, jaw condition, and slider rail play, with air lines and electrical pigtails inspected for chafe and repairs. Cab upholstery and sleeper trim should be checked for high-mileage wear at entry points, seat base play, HVAC function, and dash switchgear, with special attention to air leaks, suspension bushings, steer tire wear patterns, and brake lining thickness to confirm alignment and running gear condition.