68RFE Transmission Overview: From its origins in 2007.5 to its infamous weaknesses and the proven solutions offered by ATS Diesel Performance, this article takes a deep dive into the history, issues, upgrades, and ultimate alternatives available for RAM Cummins owners. Whether you’re considering a rebuild, a valve body upgrade, or a full Allison swap, here’s everything you need to know.

Origins of the 68RFE

The 68RFE transmission was introduced in 2007.5 as the answer to the rapidly escalating horsepower wars among diesel truck manufacturers. RAM needed a transmission that could stand against Ford’s TorqShift and GM’s Allison. On paper, the 68RFE looked competitive, but its architecture was born from the smaller 45RFE and 545RFE transmissions found in gas-powered SUVs and even minivans. This ancestry left the 68RFE with a foundation that was never truly designed for the massive torque of the 6.7L Cummins.

With a six-speed configuration and electronically controlled shifting, the 68RFE was marketed as a modern solution. Unfortunately, it quickly revealed itself as fragile under real-world conditions. Heavy towing, larger tires, performance tuning, and even daily work use exposed design flaws. From the beginning, it was clear that the 68RFE was a compromise solution—not the heavy-duty workhorse Cummins owners expected.

68RFE Fluid & Service

Routine maintenance is critical for keeping a 68RFE transmission alive. Factory fluid capacity is about 17 quarts with torque converter, though service changes usually require less. Owners frequently ask about 68RFE fluid capacity, oil capacity, and the best transmission fluid for 68RFE. Using a high-quality ATF+4 fluid is essential, and many enthusiasts step up to upgraded pans and filters.

ATS addresses this weak point with its 68RFE Deep Transmission Pan. The deep pan increases fluid capacity, lowers operating temperatures, and includes a magnetic drain plug for easier service. Paired with a filter kit or 68RFE Accessory Upgrade Package, owners can dramatically improve reliability and reduce the risk of burnt clutches and overheated solenoids.

Common 68RFE Failures & Issues

Despite regular service, 68RFE transmission problems are well documented. These include:

• Weak torque converter: prone to overheating and ballooning under load.
• Fragile valve body: cross leaks and hydraulic losses lead to poor shift quality.
• Undersized clutch packs: burn out quickly with towing or tuning.
• Pump issues: inadequate pressure at higher loads.
• Electronics: solenoid pack failures, erratic shift solenoids, and pressure sensor issues.
• Thermal bypass valve: prevents proper fluid circulation until hot, often causing early wear.

These flaws make the 68RFE a liability in stock form. When adding horsepower, tuning, or towing heavy loads, the failure rate increases exponentially.

68RFE Rebuild Kits & Transmission Packages

Owners searching for a 68RFE rebuild kit or remanufactured 68RFE transmission often find themselves weighing cost versus long-term durability. A basic rebuild can replace worn clutches and seals, but true reliability requires billet shafts, upgraded pumps, and heavy-duty torque converters.

ATS Diesel Performance offers complete solutions such as the ATS 68RFE Transmission Package (4WD) and ATS 68RFE Transmission Package (2WD). These packages integrate upgraded torque converters, billet parts, and proprietary tuning to withstand power levels far beyond stock.

By comparison, piecing together a stage 2 rebuild kit or rebuild kit with torque converter can cost thousands—and still leave you with factory limitations. A full ATS package is engineered to address every known weak point.

Valve Bodies

The valve body is the heart of hydraulic control in any transmission. In the 68RFE, stock valve bodies are infamous for cross leaks and weak channel plates. ATS offers multiple solutions:

• ATS 68RFE Performance Valve Body – Designed for improved line pressure and shift quality.
• ATS 68RFE Billet Channel Plate Valve Body – Reinforced billet plate eliminates flex and hydraulic loss.
• ATS Billet Channel Plate – A standalone upgrade to strengthen the valve body assembly.

These upgrades are vital for anyone experiencing valve body replacement issues, shift flare, or looking for a true valve body upgrade kit.

Torque Converters & Hard Parts

The stock 68RFE torque converter is one of the weakest links. Designed with a thin cover and limited clutch surface area, it overheats and fails quickly. ATS addresses this with its Five-Star Torque Converter, included in transmission packages. Billet input shafts and reinforced pumps are also available for high-power applications.

These upgrades not only increase holding power but also reduce slip, heat, and wear, making them essential for tuned or heavily worked trucks.

Electronics & Tuning

The 68RFE relies on a solenoid pack and electronic controls to manage shifts. Failures in the solenoid pack or shift solenoid are common. Additionally, drivers often experience issues with pressure sensors and relearn cycles.

ATS provides a unique solution with its ATS Co-Pilot system. This controller adds intelligent pressure management and protects clutch packs, especially under high torque loads. Paired with tuning platforms, the Co-Pilot gives RAM owners a level of drivability and control the factory never achieved.

Thermal Management

The 68RFE thermal bypass valve is designed to keep fluid warm until the truck reaches operating temperature, but in practice it often starves the transmission of cooling flow during heavy use. Failures here are so common that “thermal bypass 68RFE” searches are among the top for this transmission.

ATS developed the 68RFE Thermal Bypass Upgrade, which deletes the problematic valve and ensures full-time flow through the cooler. This dramatically reduces fluid temperatures and extends transmission life, especially when towing or hauling in hot climates.

68RFE vs. Aisin

For years, RAM offered the Aisin AS69RC as an alternative to the 68RFE in heavy-duty applications. While marketed as “commercial grade,” the Aisin suffers from its own issues: weak clutch packs, sluggish shifting, and locked electronics that prevent tuning. In head-to-head comparisons, both the 68RFE and Aisin fall short of expectations, leaving many owners frustrated with expensive repair bills and inconsistent drivability.

Allison Conversion: The Ultimate Fix

The long-term solution for many Cummins owners is to ditch both the 68RFE and Aisin in favor of the legendary Allison. The Allison 1000 is proven in GM Duramax and medium-duty applications, and thanks to ATS Diesel Performance’s Allison Conversion Kits, it’s now available for RAM Cummins trucks.

ATS conversion systems include a patent-pending bellhousing, complete hardware, and the ATS TRANSLator module that preserves all OEM functions:

• Push-button start
• Cruise control
• Tow/haul and Tap-shift
• Electronic range select
• Transfer case integration

With Full Allison Conversion Kits, owners can choose stages rated from 700 hp to over 1,100 hp. For those tired of repeated 68RFE failures, the Allison swap is the most reliable long-term investment.

Gear Ratio Comparison

The 68RFE has earned its reputation for being fragile. While ATS offers industry-leading upgrades—valve bodies, torque converters, deep pans, Co-Pilot electronics, and complete transmission packages—the ultimate solution for some is an Allison conversion. For owners committed to the 68RFE, ATS upgrades transform it from a liability into a dependable workhorse. For those seeking maximum durability and drivability, the Allison swap remains unmatched.

Whether you’re looking for a built 68RFE transmission or a complete Allison conversion kit, ATS Diesel Performance delivers the parts and engineering to keep Cummins trucks on the road for years to come.