2023 Kenworth T680

Category, Trucks. Mileage profile, 665,608 miles points to sustained highway duty cycles and a chassis that should be judged on cumulative wear rather than age. Service history matters here, look for documented overhead set, aftertreatment maintenance, coolant/oil sampling, and any prior inframe or head work. Powertrain details, engine, transmission, and axle ratio are not provided, so application fit cannot be confirmed from specs alone. Inspection focus should land on blow-by level, crankcase pressure, CAC plumbing seepage, charge air cooler boot condition, and evidence of active oil leaks at the front cover, oil pan rail, and rear main area. Aftertreatment condition should be verified with a scan for parked regen frequency, SCR efficiency faults, NOx sensor history, and DPF ash load, along with a visual check for tampered clamps, fresh hardware, or mismatched sensors. Frame rails, look for corrosion at fastener points, elongated holes around suspension hangers, and any signs of prior repairs near the fifth wheel area. Fifth wheel, check jaw wear, top plate galling, slider rail straightness, and air line routing for rub-through. Cab and sleeper, verify seat base play, pedal wear, steering wheel free play, HVAC performance, and any coolant smell at the heater core area, then confirm all dash functions and switchgear under load. Wheels, tires, and brakes, measure remaining lining, check rotor or drum heat checking, inspect hub seals for weep, and note any irregular tire wear that could point to alignment, bushing wear, or ride height issues. Identification, serial 1XKYD49X6PJ233713 and stock 0635238 should be matched to door tag, ECM report, and any maintenance records to confirm mileage consistency and component serials.