Aisin AS68RC Transmission Rebuild & Repair in Glendale, AZ (Ram HD)

Sun West Transmissions — Glendale, AZ. Free estimates, honest diagnosis and a 3-year / 40,000-mile warranty on qualifying rebuilds and replacements.

The Aisin AS68RC is a heavy-duty six-speed automatic built by Aisin, the Japanese transmission maker, for commercial-grade trucks. Ram adopted it for its heaviest Cummins diesel applications starting in the late 2000s, offering it alongside the 68RFE. Where the 68RFE served most 2500 and 3500 pickups, the AS68RC was used in chassis cab trucks and, later, in high-output Cummins pickups that needed more torque capacity. It is known for durability, but it is not immune to heat, heavy loads or neglected maintenance.

Sun West Transmissions in Glendale services, repairs and rebuilds the AS68RC for fleet operators, contractors and owners of high-output Ram trucks. Diesel and heavy-duty work is part of what we do every week.

Where You Will Find the AS68RC

• Ram 3500, 4500 and 5500 chassis cab trucks with the 6.7L Cummins
• Ram 3500 pickups with the high-output Cummins in certain years
• Some Ram 2500 and 3500 configurations ordered with the Aisin option

Later high-output trucks moved to the updated Aisin AS69RC. Standard-output trucks often use the 68RFE. We verify the transmission before quoting any work.

What Sets the AS68RC Apart

The AS68RC was designed with commercial use in mind. It has a stout case, heavy-duty clutch packs, close-ratio gearing for towing and provisions for a power take-off on chassis cab trucks. It works closely with the engine’s exhaust brake and uses electronic control to manage shift timing, converter lockup and grade braking. Because the truck’s engine, exhaust brake and transmission controls all interact, diagnosing it requires looking at the whole system.

Common AS68RC Problems

Harsh or Inconsistent Shifts

Some trucks develop harsh upshifts or downshifts, a bump coming to a stop or inconsistent shift feel. Software calibration and adaptive learning are often involved, but solenoid wear or valve body issues can cause the same symptoms.

Slipping Under Heavy Load

Chassis cabs with flatbeds, dump bodies or service bodies often run near their limits. Over time, clutch packs wear, and the truck may flare or slip under load. Slipping creates heat, so it should be addressed quickly.

Overheating

Long climbs with heavy trailers or loads, plus Arizona summer temperatures, can push fluid temperatures high. Burnt fluid leads to glazed clutches, varnished valves and seal failure. The cooler and cooler lines should be part of every inspection.

Torque Converter Issues

Converter clutch wear or shudder can show up as vibration at steady speed and higher temperatures. Because Cummins torque is so high at low RPM, converter health is critical.

Leaks and Electrical Faults

Seals, pan gaskets, cooler line fittings and connectors can leak or fail with age. Electrical faults may trigger warning lights or limp mode.

How We Diagnose an AS68RC

We scan the transmission and engine modules, review codes, live data and adaptive values, check fluid level and condition using the correct procedure and road test the truck. When practical, we test under load because many heavy-duty complaints only show up when the truck is working. We also check the exhaust brake operation, cooling system and PTO if equipped. Visit our heavy-duty truck transmission repair page for more.

AS68RC Repair and Rebuild

Repair options range from software updates and solenoid or sensor replacement to a complete rebuild. A full AS68RC rebuild includes removal, complete disassembly and cleaning, new clutches, steels, seals, gaskets and filters, replacement of worn bushings and hard parts, valve body service and torque converter service or replacement. We flush the cooler, reinstall, fill, perform any required relearn and road test.

• Cooling system upgrades for working trucks
• Fleet scheduling options; see our fleet transmission service page
• Qualifying rebuilds include our 3-year / 40,000-mile warranty

AS68RC Rebuild Cost

Cost depends on what failed, how far damage spread, the converter, parts availability and cooling needs. We do not quote numbers before diagnosis, but estimates are free. Our diesel transmission rebuild cost guide explains the factors, and financing is available for qualifying customers.

Keeping a Commercial Ram Working

Work trucks earn money only when they run. Regular fluid and filter service on a severe-service schedule, a healthy cooling system and early attention to shift changes keep downtime low. Our transmission care for work trucks article has practical tips for owners and fleet managers.

Aisin AS68RC Transmission FAQ

Is the AS68RC better than the 68RFE?

They are built for different jobs. The AS68RC is a heavier-duty commercial unit, while the 68RFE serves most pickups. The right one depends on the truck and its use.

Can the AS68RC be serviced like other automatics?

Yes, but it requires the correct fluid and fill procedure. Using the wrong fluid or level can cause shift problems.

My chassis cab shifts harshly with a load. Is that normal?

Some firmness under load is normal, but a sudden change in shift feel is not. Have it checked before the problem grows.