If you're a motivated and engaged late model 6.7 Power Stroke owner, you might know that Next Gen Drivetrain has been vehemently engaged with the 10R140 transmission, building them for a diverse spectrum of applications. All to often, we are approached with question after question about this highly complicated transmission; ranging from what fails to why and how. Fortunately, we've fulfilled this demand with an installment in our popular Drivetrain 101 series.
It should be noted that this transmission is the fraternal twin to the Allison 10L1000 Transmission, fitted to the corresponding years of DuraMax diesel. This product was engineered as a joint venture between Ford and GM (General Motors). They are slightly different, in that Allison owns multiple intellectual property items that they've implemented to their version of this transmission, as did Ford. Because of this, they are not identical.
Our goal is to educate, inform and support the 6.7 Power Stroke market with high quality data and facts about their transmission. As transmissions and vehicles in general become ever more complicated, it's important to educate yourself on how these mechanisms operate. If you want to become an expert on the 10R140 transmission, this Drivetrain 101 is for you!
In this Drivetrain 101, we will be addressing:
- The most popular failures we witness on the 10R140 transmission
- Ways to get the most out of your transmission
- The strengths (believe it or not, there are a few!) of this transmission
- Resources for relevant updates and upgrades
Prior to 2020, the 6.7 Power Stroke came with the respectable 6R140 transmission. Unfortunately, as the ferocity of these motors increases, the 6R140 transmission quickly became ill equipped for the job. Because of this, Ford (and GM) had to pursue a new option. Due to their massive capital reserve, Ford was able to engineer their own transmission just as they did with it's predecessor.
After years of research and development, out came the 10R140 transmission. The new 10 Speed is able to hold considerably more power, using more robust components internally. Additionally, it is designed to keep the motor inside a narrow operating range to favor efficiency. 10 Speed transmissions, in general, largely just exist as an appeasement to the EPA. It could easily be argued that a stronger 6R140 would have easily sufficed.
At this time, there is no forseeable successor to the 10R140 transmission, it is likely to stay with us for the next few years. But, despite it's various enhancements over it's predecessor, the 10R140 transmission is not perfect. In fact, many people experience a rapid decline in transmission health with so little as 35" tires (sorry Tremor guys), nevermind removing emissions components or using a tuner. Although we love power as much as you do, we must be sober about the fact that power leads to broken transmissions much sooner. Fortunately, we will discuss how to resolve this later in the study.
How the 10R140 Clutch Packs Work:
Like nearly all electronic transmissions, the 10R140 transmission uses a shift map using various factors such as engine load and accelerometer input to calculate shift decisions without your input. Very similar to it's Allison counterpart, the 10R140 uses a form of adaptive shift protocol to optimize for smooth shifts. The onboard computer is constantly trying to advance or delay solenoid activation to support this goal.
Here, we can see a solenoid application chart. As one could see, there are MANY different solenoids in this transmission, all designed to operate in a complex and cohesive fashion. Naturally, this intensely complicated system can be prone to prolific electrical issues as well as valve bore wear issues, largely because of how many of them there are. Many clients report clunky, poorly timed or "confused" shift behavior as these problems present.
As a clutch to clutch style transmission, this means that the 10R140 does not use any bands, servos, levers, anchors or struts to activate any of it's functions. This is not necessarily a benefit or a drawback, but rather just a useful piece of information. Band & Servo style units were discontinued years ago due to their general inability to be electronically controlled. As we have all seen over the past years, OEM's are eager to electronically control transmissions. Now that we've learned about these foundational facts, we can analyze the problems of the 10R140 transmission and how to resolve them.
Problem #1 - The Torque Converter
Similar to the Allison 10L1000 transmission, the OEM torque converter is very stout in some ways, and very unprepared in others. The impeller hub, which is the piece that splines into the oil pump, is massive and very unlikely to break. Granted, it's not invincible, it's just stronger than many historical converters manufactured by Ford. We do offer a billet CNC machined hub on all of our torque converters, so this concern is nil with our product.
More prolifically, the converter clutches fatigue, flex and burn over time. They're quite fine on day one, but notorious for longevity issues. It's almost identical to the 6R140 Transmission in terms of the torque converter lockup clutches and how they work. To some consolation, the 10R140 is a line pressure monster, producing ample pressure to hold the clutches together assuming no other collateral failures take place.
Additionally, the OEM stator, the component responsible for controlling stall speed, is absurdly high stall. This is because stators have a notable impact on idling emissions, something the EPA is deeply concerned about. To the benefit of our consumer, we don't give a shit about the EPA. Our priority is on reliability, functionality and driving dynamics; things relevant to you as the owner of the vehicle.
Lastly, and as a collateral effect of the stator, the OEM converter escalates average operating temperature (AOT) by a considerable margin because the large allowable difference in speed between the motor side and the input shaft side of the converter is so immense. This generates huge amounts of thermokinetic energy, a chemical reaction producing heat. Heat is a silent killer in the transmission world, and detracts from the longevity of any transmission.
Problem #2 - The Valve Body
As with many transmissions, the 10R140 transmission's valve body is a huge cause of it's demise. Valve bodies are naturally complicated hydromechanical mechanisms with a huge concentration of moving parts and electronics. This makes them probable targets for internal crossleakage, solenoid failure and other similar problems that are notorious for cooking transmissions to death.
Firstly is the pressure solenoids inside the valve body. There are many of them as nearly all functions of this transmission are controlled by a switch or solenoid. As with most mechanisms, more moving parts means more things that can break. Generally, these solenoids are reliable, however they are often victimized by internal crossleakage inside the valve body that puts undue stress on the electronics by trying to push them on when the onboard computer believes they should be closed, or vice versa.
Additionally, the valvetrain inside the valve body is quite abundant, featuring dozens of moving parts. Every valve is a potential leakpoint. This would not be of concern if the transmission's valve body featured steel valves or anodized protective layers on the exterior of said valves, but unfortunately they are not. The valves are manufactured out of a low cost aluminum alloy designed to minimize cost at volume, leaving them susceptible to bore wear over time.
Further, the separator plate inside the valve body does not favor fast and efficient shifts. In fact, the separator plate contributes to many "sloppy" shifts by featuring unfavorable oil geometry when oil is trying to reach oncoming clutch packs. We expedite oil flow into oncoming clutches by making substantial modification to the OEM separator plate. To be fair, the OEM separator plate is rather thick and difficult to flex, but is inferior in other ways as mentioned. This makes modification of the OEM plate the most favorable way to ensure reliability as well as peak operability.
Problem #3 - The Oil Pump
Much akin to the Allison 10L1000 transmission is the 10R140 transmission's oil pump. The high pressure oil pump inside this transmission is incredibly complicated for no visible reason. It features dynamic veins and a rotating wheel driven by a steel gear with it's own filter. This design is generally reliable but requires abundant filtration to maintain said reliability, making regular service important.
In terms of failure, the OEM transmission tends to shed a large amount of friction material over time due to the low quality friction elements used from the factory and the intense amounts of clutch drag they suffer from due to their slow engagement and sloppy shifts. This naturally exacerbates and accelerates the wear issue of the OEM oil pump in unmodified 10R140 transmissions.
In addition to this, the 10R140 oil pump is notorious for losing oil pressure at the top end as this problem begins. This causes the transmission to shift erratically or sloppily under full throttle or with loads being towed. There beyond, these transmissions rely on oil pressure to calculate their shift behavior, contributing to tremendous confusion of the onboard computer whilst adapting to your driving patterns. This is one of many reasons the factory 10R140 transmission's shift strategy is so unpredictable.
Problem #4 - The "E" Clutch Assembly
As the commonalities amongst the Allison 10L1000 and the Ford 10R140 transmissions grow, we must mention the "E" clutch assembly. Although this clutch assembly does not have the highest torque multiplication factor, it does have a rather high one as it is used in most overdriven gears. The reason it is so quick to fail is because of a combination of this and the fact that the clutches are rather small in surface area.
Similar to the reason a car's smaller rear brakes do not provide as much stopping power as the larger front brakes, small friction plates offer less synchronization power than large ones. As a result, the "E" clutch assembly is disadvantaged from the factory. Granted, the OEM is not incentivized to provide over-built transmissions to the consumer, but rather transmissions that are low cost to produce and generally sufficient to see customers to the end of their warranty period providing they do not modify or overuse the vehicle.
Fortunately, we use a host of modifications to the valve body to enhance oil pressure to the "E" clutches as well as modify the separator plate to bring these clutches on much faster. The decrease in synchronization time enhances both shift quality AND longevity. It is unfortunate that the OEM did not care to provide benefits like this to the consumer.
Problem #5 - The Oil Pan
As an expensive 10 speed transmission, it is exceptionally important to maintain low oil temperatures to preserve the longevity of the transmission. From the factory, the OEM saves money by stamping the oil pan out of thin steel using a mold and a special tool to provide accurate shape. This is never optimal, but certainly does not endorse a healthy transmission for heavy duty applications or long term use.
In fact, the OEM oil pan is so lacking in volume that a variety of transmission pan manufactures have added in excess of a gallon to the oil volume of this transmission. Due to the obvious nature of this upgrade, it is standard on ALL Next Gen Drivetrain 10R140 transmissions to contain a cast aluminum deep pan.
Another lost benefit when operating with an OEM oil pan is the lack of structural support to the case. Cast aluminum deep pans function as a "girdle" that supports the case to prevent flexion, greatly decreasing the potential for a broken case. Although broken cases are not very common to this transmission, it does exist and should be noted. A cast aluminum deep pan virtually eliminates this concern.
Problem #6 - The "B" Clutch Assembly
As the clutch pack active for 8th, 9th and 10th gear, the "B" clutch assembly features the greatest torque multiplication factor of any clutch pack inside the 10R140 transmission in most conditions. Much as the "E" clutch assembly suffers from inadequate apply pressure and inadequate oil feed rates, so does the "B" clutch assembly.
The "B" clutches are intermediate in size and would certainly be successful with access to better shift strategy and oil geometry, but unfortunately, the OEM does not provide this. The oil feed orifice inside the OEM separator plate is physically larger in Next Gen 10R140 transmissions, giving this clutch pack a far better chance at life.
To augment these efforts, the pressure regulator valve spring is also changed to require greater oil pressure before venting. This means more oil reaches the clutch pack, in a more timely fashion, tendering the support necessary for this transmission to endure the use of a more powerful or heavily used vehicle. Although all clutch packs are enhanced in some way in our product, it is important to highlight clutch packs such as "B" which are exceptionally at risk.
As one could see, the 10R140 transmission is lacking in mechanical and hydraulic quality. This transmission was never meant to be a "premium" option, but rather a high volume, economical option that favors EPA regulation. Fortunately, Next Gen has been adamant about bridging the gap between this naturally inferior transmission, and it's potential for tremendous success and reliability. Have questions about the 10R140 transmission? Call in and speak to one of our experts today!