2026 Mack GR64F

Application fitment centers on heavy vocational and upfit work, cab and chassis layout with 297-inch wheelbase leaves room for bodies, tanks, dumps, or roll-off gear. Mileage shows essentially delivery-level use, so wear should be limited to initial shakedown items like clamps, fasteners, and fluid seep checks. Powertrain pairing uses a Mack MP8 rated at 455 hp tied to a Mack mDRIVE HD 13-speed with creeper and multi-speed reverse, a combination that favors controlled starts under load and tight jobsite maneuvering. Rear gearing at 3.73 with 46k rears points toward startability and grade control over high-speed cruise, and the 66,000 lb GVWR with 20k front axle supports heavier front-end equipment and body loads. Chassis and running gear include tandem 46k rear axle rating with Mack AL-461 air suspension, noted as not for use with air disc brakes, so brake spec should be verified before any disc conversion plans. Frame and upfit interfaces are the main inspection points on a new cab and chassis, look for straight rail tops, clean hole patterns, intact wiring and air line routing, and no shipping rubs around crossmembers, exhaust, DEF lines, and battery box mounts. Identification points include VIN 1M2GR4GC6TM055962 and stock 71663, useful for build sheet confirmation on PTO provisions, axle ratios, and any factory wiring for body controls. ECM data is not provided, so engine hours, regen history, and parameter settings should be pulled during pre-delivery inspection.