Chrysler 68RFE Vs. Aisin AS69RC: What's The Difference Between These Transmissions?
If you've ever been in the market for a capable and dependable work truck, you'd know that choosing the correct transmission can be just as important as selecting the right engine option for your needs. Transmission options are typically designed around specific use cases, and it takes a bit of research to determine the right option for you whether you plan on hauling large loads, intend on upgrading the power output of the truck, or typically spend a lot of time cruising on the highway.
Dodge/RAM heavy-duty pickup trucks are a solid pick as far as towing capacity, reliability, and interior comfort are concerned, making RAM 2500 and 3500 trucks a popular option among working professionals and enthusiasts alike. The standard transmission for the Cummins diesel-powered RAM 2500 is the Chrysler 68RFE automatic six-speed transmission that was introduced halfway through the 2007 model year. While the 68RFE also comes as the default transmission in the 3500 with the 6.7L Cummins, the Aisin AS69RC automatic six-speed, which was introduced in 2013, is also offered as an optional transmission in low output 6.7L Cummins 3500s and as the standard transmission.
Both Chrysler 68RFE and Aisin AS69RC are known to be solid transmissions that are perfectly capable of doing the jobs that they were designed to perform. However, those jobs are different, as the 68RFE was designed around improved fuel efficiency and smooth performance while the Aisin was designed around durability and towing large loads.
Strengths and weaknesses of the Chrysler 68RFE transmission
When the 68RFE was introduced alongside the 6.7L Cummins turbodiesel in 2007, it came as a breath of fresh air to RAM enthusiasts, as it was the first quality transmission that Chrysler had put out in a while. The 68RFE features a favorable gear spread, with a tall first gear for good low-speed towing performance. The 68RFE's torque converter makes use of a lock-up clutch, reducing overall fuel consumption and increasing the smoothness of shifts. The 68RFE shifts notably faster due to the fact that it doesn't require as much of a fuel de-rate during shifts compared to the Aisin AS69RC. It is also important to mention that the 68RFE is a much more modifiable transmission compared to the Aisin, with a ton of support in the aftermarket.
Despite being a quality transmission when used the right way, the 68RFE is notoriously weak when paired with an engine making more-than-stock power. The 68RFE is rated to 750 lb-ft of torque and a maximum GVWR of 18,000 pounds. If either of those numbers is surpassed, the 68RFE is essentially known to disintegrate. The main issue is the 68RFE's torque converter that, while using a massive stator and a double-sided friction element, cannot hold the power of a modified truck. In most cases, they only last around a thousand miles on a truck pushing more than 400 horsepower. The 68RFE is also known to have input shaft and input clutch drum issues at high power and torque levels or after intense periods of heavy towing.
Strengths and weaknesses of the Aisin AS69RC transmission
The Aisin AS69RC transmission was introduced to the RAM lineup in 2013 due to the fact that the Chrysler 68RFE transmission wasn't able to cope with the forces applied to it by the high-output variant of the 6.7L Cummins turbo diesel. As a result, the AS69RC was built to be a heavy-duty transmission that could handle intensive towing applications and higher power and torque levels. Due to the reworked design, the AS69RC has a torque capacity range of between 850-950 lb-ft and a GVWR of 33,000 pounds. The Aisin's deep 3.75:1 first gear and 2.0:1 second gear ratios make full use of the Cummins' low-end pulling power and get heavy loads moving with ease.
While the Aisin AS69RC is unquestionably the stronger and more capable transmission of the two, it does have a number of shortcomings itself. One of the biggest downsides is that the Aisin AS69RC is only available paired with the High Output 6.7L Cummins, making it pretty exclusive and expensive as a result. It also has some reliability issues as well. It has a very complicated and unique torque converter that has multiple components that are prone to failure. Furthermore, it also suffers from high-pressure oil pump gear wear and issues with the valve body. The AS69RC also requires much more frequent service than the 68RFE, needing fluid changes every 30,000 miles compared to 120,000-mile intervals on the Chrysler.
Choosing between the 68RFE and AS69RC
The Chrysler 68RFE and Aisin AS69RC are both transmissions that are good at the job that they were designed for, and not much else. For that reason, it is important to consider your needs for a work truck before choosing between one or the other.
Ultimately, the 68RFE is a good, but misunderstood, transmission. It performs well and remains extremely reliable in stock trucks that aren't frequently hauling heavy loads. The problem with the 68RFE arises when additional power or heavy tow loads enter the equation. For that reason, those who are looking to take a RAM heavy-duty truck to the limits of its towing and hauling capabilities might have a better experience with the AS69RC. However, for those who value reliability and comfort while still enjoying moderate towing capabilities, it might not be worth investing the additional capital in the Aisin.
In contrast, the AS69RC is a good transmission option for commercial uses or someone who frequently needs to get the most out of the truck's hauling capabilities. With an optimized final drive ratio, an 850-950 lb-ft torque capacity, and a gross vehicle weight rating of 33,000 pounds, the AS69RC is the perfect transmission selection to push a RAM heavy-duty truck to its limit. With that being said, the AS69RC is a more technically complex and expensive transmission that requires a fair bit of upkeep to maintain its reliability. That's the price that you pay for its additional capabilities.