Aisin AS68RC 6-Speed Heavy-Duty Automatic Transmission for Sale | OEM Used Direct Fit RAM 4500 / 5500 Cummins, Isuzu, Hino, Mitsubishi Fuso, Freightliner M2

Heavy-duty 6-speed automatic transmission for medium-duty commercial trucks. The AS68RC is produced by Aisin Seiki Co Ltd of Japan (Toyota Group affiliated, also a major transmission supplier to multiple OEMs worldwide). Designed for medium-duty commercial truck applications, with input torque rating of 750-900 lb-ft and 6 forward speeds plus reverse. Combines hydraulic operation with electronic shift control through a TCM, including a lockup torque converter for highway cruise efficiency. The dominant medium-duty automatic across RAM 4500 / 5500, Isuzu, Mitsubishi Fuso, Hino, UD Trucks, and Freightliner Business Class M2.

Multiple medium-duty commercial truck OEMs. RAM 4500 / 5500 chassis cab with 6.7L Cummins (2007+ MY, dominant North American pairing). Isuzu FTR / FVR / NQR. Mitsubishi Fuso Canter FE180 / FG4X4. Hino 258ALP / 268A / 338. UD Trucks 2600 / 3300. Freightliner Business Class M2 106 / M2 112 with Cummins ISB6.7 or ISL9 pairings. Cross-compatibility within these chassis with appropriate TCM calibration and bellhousing adapter is common.

Wide range of medium-duty diesel engines across multiple OEMs. 6.7L Cummins Turbo Diesel in RAM 4500 / 5500. Isuzu 4HK1-TC 5.2L and 6HK1-TC 7.8L. Mitsubishi Fuso 4P10 3.0L and 4M50 4.9L. Hino J08E 8.0L and J05E 5.0L. UD GH7 7.0L and GH11 11.0L. Freightliner Business Class M2 with Cummins ISB6.7 6.7L and ISL9 8.9L. Each engine pairing has specific TCM calibration matching engine torque curve, shift schedule, and lockup logic to the chassis. We confirm engine pairing on every AS68RC.

750-900 lb-ft input torque rating. Designed for medium-duty commercial truck applications. The 6.7L Cummins in RAM 4500 / 5500 produces 660-800 lb-ft (year and emissions dependent), well within rating. The Isuzu 6HK1-TC 7.8L produces 590-700 lb-ft. The Hino J08E 8.0L produces 520-660 lb-ft. AS68RC torque rating includes design margin above typical engine output to handle peak transient loads, deep gear ratios, and torque converter multiplication. Aftermarket engine power increases (6.7 Cummins delete tunes, high-flow exhaust) can push output beyond AS68RC design rating, accelerating wear.

Direct mechanical engagement at cruise for efficiency. The lockup clutch mechanically locks the engine flywheel directly to the transmission input shaft at cruise speeds, eliminating slippage of normal torque converter fluid coupling. When engaged, operates as direct mechanical coupling with zero slip; improves fuel economy, keeps fluid temperatures lower, reduces wear on torque converter internals. The TCM controls lockup based on speed, throttle position, load, and grade. At low speeds, hard acceleration, or low engine load, lockup disengages for normal fluid coupling operation.

Electronic shift logic matched to specific donor chassis and engine pairing. The AS68RC operates under TCM control that manages shift timing, shift quality, lockup engagement, and adaptive learning. TCM is calibrated specifically for each donor chassis and engine: a RAM 4500 / 5500 6.7 Cummins calibration differs from an Isuzu FTR 6HK1-TC, which differs from a Hino 268A J08E, and so on. When ordering used AS68RC, TCM calibration must match the destination chassis and engine combination; we document TCM calibration from the donor truck and disclose any mismatches.

Automatic adjustment of shift quality based on driving conditions and component wear. The TCM adaptive learning detects clutch wear and adjusts shift command timing to maintain consistent shift quality. The algorithm also learns driver preferences within calibration limits. When installing a used AS68RC in a new chassis, adaptive learning typically requires 50-200 miles of varied driving to fully adapt. Some scan tools allow TCM relearn procedures to reset adaptive parameters to baseline. We verify adaptive learning algorithm operation on every AS68RC before delivery.

No. There is no core return required.