It was way back in 2007 that Dodge released the 68RFE transmission. Initially, the six-speed gearbox was considered a great upgrade for Ram owners. Unfortunately, performance enthusiasts soon learned the new transmission had some serious limitations. and the 68RFE garnered a mediocre reputation at best. Even behind an engine with stock power output, failures can still be realized. Add in more power or a heavy load behind one, and failure becomes even more common due to the added stress.
So, to help you guys avoid a certain catastrophic event with your 68RFE, we reached out to the experts at ATS Diesel Performance to figure out what can be done to make a 68RFE stronger and more reliable. Our conversation with Blake Saffell definitely opened our eyes to a few serious issues and what enthusiasts need to consider.
Are there any subtle signs a 68RFE is going out before it starts slipping?
Some see codes from cross-leaks in the valvebody. These codes are indicative of a transmission going out and having measurable hydraulic issues going on inside the transmission. The problem is, these codes often derate line pressure and can cause further damage by allowing the clutch packs to slip as clamping force is lost. Other common failures are delayed shifts, excessive heat, and fluid pushing out of the fill tube.
What makes a failure of the 68RFE transmission so common?
With a completely stock truck that is used for light towing, a stock 68RFE can be a relatively reliable transmission. Unfortunately, with the 68RFE, that is rarely the case. Essentially, Chrysler tried to upgrade a gas transmission meant for a small HEMI V8 and has yet to go back to the drawing board to try to improve it since it was released in 2007. The shafts are small and the valvebody is made from thin, cheap aluminum that can flex and allow for cross-leaks between the clutch packs. The case is weak, and the clutches are small. What’s more, the pump can barely provide enough pressure to give the 68RFE a chance in the first place.
Is there a certain mileage when the 68RFE starts having problems?
Not really, we see people having trouble with 68RFEs at any mileage. The more power/torque the engine makes, the bigger the tires, and the more weight being towed, all significantly lower the mileage longevity; they will increase the mechanical disadvantage the 68RFE faces with its low line pressure and small clutch packs.
What is the build process of an ATS 68RFE?
When a core comes into ATS, it goes through a thorough inspection, cleaning, and preparation process. After that, several parts are sent upstairs to our machine shop. Our in-house machine shop allows us to perform a number of operations on the valvebody. One of those is a clean-up and crosshatch introduction to the accumulator piston bore. This is done to ensure a smooth, consistent surface and oiling cross hatch for each piston. We also machine this side of the valvebody to ensure a completely flat surface to match up to our BilletProof Channel Plate that we CNC machine from a 1-inch-thick piece of high-grade solid aluminum.
Clutch modifications are generally one of the most impactful and important items that can be upgraded in any transmission. In the case of the 68RFE transmission, there is little room for additional clutches, so modifications must be done to pressure plates to provide increased clutch surfaces. The underdrive (Forward) clutch pack surface area is increased by 21 percent, using single-sided clutch plates. The overdrive clutch pack surface area is increased by 17 percent, also using single-sided clutch plates. This allows for better clutch control when overdrive is used at higher power levels. The 2C clutch pack surface area is increased by 34 percent, using double-sided frictions.
Next, the 4C clutch pack surface area is increased by 34 percent, using double-sided frictions. The weak mechanical low one-way sprag is replaced with a stronger roller clutch design that uses a “cam and roller” system. The factory sprag not only has a very weak torque capacity, but it also fails because of a lack of proper lubrication. The stronger low roller clutch design used by ATS prevents the higher mileage failure associated with the sprag-type clutch.
We reinforce and weld the pinon gears in the planets for added strength as well as several other parts such as the overdrive and underdrive hub. An ATS Case Brace and ATS Deep Pan are added to every stage, and that solves a large majority of the weak case issues.
Our Five Star torque converter is completely manufactured from scratch with our patented square tab technology, a dampener, a billet piston, ball bearings, and a stator that we CNC here in-house.
The validation part of our build process involves testing the solenoids on a solenoid tester, our valvebodies on a valvebody tester, and the completed unit on a transmission dyno.
What are the differences in the stages of the ATS 68RFE transmissions?
The only difference between each stage is the addition of two billet parts. Stage 2 gets a billet input shaft, and Stage 3 gets an input shaft and billet OD clutch drum. All the other modifications and billet parts, like the billet channel plate and high-volume billet pump, come standard in every stage of the ATS units we build.
How does the stage 1 ATS compare to a factory transmission?
There’s really not much comparison between an ATS Stage 1 and a stock 68RFE transmission. The ATS 68RFE is a very robust transmission. It is professionally built and tested while using the highest-quality parts. So you know you are getting a proven transmission ready for whatever you can throw at it. It would be hard to put a stock 68RFE back into a truck, knowing the problems it carries and that it is all luck of the draw on how long it will last before giving you more problems.
Although the 68RFE does have its limitations and shortcomings, it’s nice to know that you do have options when you want to build a better transmission that will likely outlast your truck.