Common Problems With RAM Aisin Transmissions (According To Owners)

Aisin is a Japanese automotive components manufacturer that partnered with BorgWarner in 1969 to develop high-torque transmissions widely used in heavy-duty trucks. Although they might not be popular outside the industry, Aisin transmissions have made significant contributions to the truck world. Its transmission systems feature in several popular automotive brands from the Suzuki Samurai to the Jeep Cherokee, Mitsubishi Pajero, Nissan Titan, and most notably, the RAM HD lineup.

The 6.7L Cummins and 6-speed automatic Aisin transmission combo is well-known for durability and towing capability among heavy-duty pick-ups and light trucks. The Aisin transmission features in several Ram trucks. The AS68RC was fitted in the Ram 3500/4500/5500 between 2007 and 2012, while the 2013 to 2022 Ram received the AS69RC. The latter Aisin transmission was marketed as a better alternative for towing and heavy-duty handling than the 68RFE (six-speed automatic transmission used in earlier Dodge and Chrysler models).

On paper, the Ram Aisin transmissions are expected to be durable and reliable. However, owners on popular Cummins forums and Reddit have reported various recurring issues revolving around a K1 Clutch Snap Ring, jerky and sloppy shifting, and overheating.

Aisin is known worldwide for developing some of the most robust automatic transmissions for light trucks and heavy-duty pickups. Still, owners have experienced some issues with the AS69RC transmission over the years. After receiving some complaints, the NHTSA (National Highway Traffic Safety Administration) started looking into the failures. Ram had also released a technical service bulletin on their network (#21-002-23), pointing out the problem around a K1 Clutch Snap Ring Repair on 2021 and 2023 Ram HD models.

Some of the most common issues reported by owners included jerky or sloppy shifting that led to laggy acceleration. Between 2013 and 2021, the Aisin transmission on Ram HD vehicles also experienced delays or sharp shifts between the 3rd and 4th and 5th and 6th gear, worsening fuel economy. According to users, the system was unable to determine the correct gear during strenuous tasks like hauling or driving up a hill.

Other owners reported transmission overheating issues during heavy towing and steep inclines that sometimes triggered the limp mode. However, the worst of the reports was early failures on the Aisin transmission (some as low as 200 miles). "All were purchased new this year, have less than 7k miles on them, and I have lost transmissions on 6 of them (2 of them are on their THIRD transmission), and they went down within 100 miles of being replaced," a Ram fleet owner confessed on Reddit.

There's a huge debate among Cummins diehards about the durability and reliability of the AS69RC versus the 68RFE. Some Cummins owners feel the Ram HD trucks should have retained the 68RFE, confessing that they traded down their units with Aisin transmissions for the older variants, while others feel the problematic AS69RC is bulletproof with minor upgrades.

According to the Cummins forum, the failures in the Ram Aisin transmissions are caused by a poorly manufactured K1 input shaft drum sub-assembly and K1 clutch snap ring on the 2022 and 2023 Ram 3500/4500/5500 trucks. The failures will trigger warning lights and present a P0731-00 trouble code.

The general consensus among Ram truck owners on multiple forums on maintaining Ram Aisin transmissions (regardless of year and application) is to constantly monitor transmission temperatures during strenuous driving, stay up to date with regular service and maintenance, and consider signing up for extended warranties. Those in the market for Ram HD trucks are advised to be cautious about buying early models manufactured between 2013 and 2022.