Posted by Jason Locke on 12/13/2024 to
News
The 6.7L Cummins under the hood of your 2007.5-2024 Ram 2500 or 3500 is capable of hitting some seriously big power numbers with relatively few modifications and performance upgrades, but it's no secret that the 68RFE transmission sitting behind that big Cummins diesel has more than its fair share of problems that can crop up at stock power levels. Once you start adding some serious horsepower and torque, those problems go from annoying to potentially catastrophic. The Tier One 2007.5-2018 Ram 68RFE Stage 3 Transmission and 2019-2024 Ram 68RFE Stage 3 Transmission are purpose-built from the ground up to handle huge levels of power, aggressive applications, and extremely heavy towing without letting you down. While the Stage 3 transmissions may not be able to hold the same power as our competition units, the Stage 3 68RFE transmissions are a great choice for Ram trucks that are throwing down a whole bunch of power, but are still primarily street, trail, and towing rigs. We're going to take a look at all the parts and components we put into the Stage 3 transmissions so that you can see how we put these badass built 68RFE transmissions together. If you're a more visual learner, check out the video below of Tanner putting together a Stage 3 68RFE for one of our customers. Find even more build and breakdown videos over on our YouTube Channel!
For each billet high-pressure valve body build, we here at Tier One start by wet-sanding valve body to ensure that they're perfectly flat. The OEM valve bodies are very rarely totally flat, which means that even if you use a bonded separator plate, you can still run into spots were the ridges of the worm channels aren't making good contact. Once the valve body is completely flat after a wet-sand, we here at Tier One install billet accumulator pistons that have much greater strength than stock and feature redundant seals to prevent leaks and pressure losses. The high-pressure billet valve bodies get a new Solenoid Switch Valve (SSV) that's smoother than the stock valve to prevent pocket wear into the valve body itself which can lead to failures. The valve body gets a bonded separator plate to help keep the worm channels properly sealed, and is much more effective than competing valve bodies thanks to our wet sanding. In order to handle the high levels of power that the Stage 3 transmissions are destined for, we throw in a billet channel plate that much less likely to warp under load than the stock cast aluminum channel plates. Finally, the valve body gets a new OEM solenoid pack that goes through extensive testing to ensure better than OEM functionality.
The billet clutch drums we use in the Stage 3 68RFEs also have room for more clutches, and we increase the clutch counts in the overdrive, 2C, and 4C clutch packs so that the transmission can reliably handle, hold, and transfer big horsepower and torque through your Ram's drivetrain. The increased clutch count adds total surface area in the clutch packs and gives you more friction surface area to hold onto power.
The PPE 68RFE pan also comes with large cooling fins that further increase heat dissipation, which is great for helping reduce peak transmission temperatures in tough applications. One of the big reasons we here at Tier One prefer PPE pans is the large drain plug with oversized head that makes it much less likely to strip out than the drain plugs on other transmission pans. The PPE pans also come standard with NPT ports that let you run manual sensors and temperature gauges without having to drill the pan.
The Brains of the Stage 3 68RFE: Tier One's High-Pressure Billet 68RFE Valve Body
One of the most important parts of any modern transmission is the valve body, and the 68RFE valve bodies have a ton of issues that lead to low line pressure, lack of lubrication to critical transmission components, weird shifting behavior, and other issues. The stock 68RFE valve bodies suffer from cross-leaks and pressure losses that can lead to the poor operation of your transmission's clutch packs and torque converter, if not outright causing a failure that will leave you and your truck stranded. For our Stage 3 68RFE transmissions, we here at Tier One install our 2007.5-2018 Ram 68RFE Billet High-Pressure Valve Body or 2019-2024 Ram 68RFE Billet High-Pressure Valve Body into every Stage 3 build. Our Billet High-Pressure Valve Bodies feature a bunch of reliability and power-holding improvements that prevent cross-leaks, pressure loss, and warping when under immense levels of load.Reliably Transferring Power: SunCoast Billet Triple-Disc Torque Converter
The stock torque converter that mates the 68RFE to your Ram's 6.7L Cummins diesel can only handle so much strain, and when you're throwing down a huge amount of power from bigger turbos, oversized injectors, upgraded fuel pumps, and aggressive tuning, the stock torque converter will let you down in all sorts of "fun" and potentially catastrophic ways. For holding big power reliably, there's no one we here at Tier One trust more than SunCoast, and we drop one of their billet triple-disc torque converters into every Stage 3 68RFE transmission. SunCoast's torque converters are expertly manufactured with flawless machining and craftsmanship that is practically unparalleled across the entire industry. Each of these torque converters features a billet steel cover that's far stronger than stock and includes three carbon-graphitic clutches that provide huge clamping force and power-holding in even the most extreme applications.Holding Power & Handling Converter Force: Billet Maraging Steel Input Shaft
The input shaft leading into your Ram's 68RFE has to deal with a lot of load, and when you stack on some seriously huge power, you'll need an input shaft that's not just billet, but something even stronger to keep your truck on the road and throwing down horsepower and torque. For each of our Stage 3 68RFE transmission builds, we include a billet maraging steel input shaft. Maraging steel has even greater strength than standard 4130 or 300-series billet steels, allowing a billet maraging steel input shaft to handle the huge force loads from extreme power and aggressive applications, as well as the clamping force that the SunCoast triple-disc torque converter is capable of throwing out. The billet maraging steel input shafts we use on the Stage 3 68RFEs have far more torsional strength than stock or standard billet input shafts, allowing them to avoid cracking, spiral fractures, or even outright shearing under enough force.Preventing Overdrive Shaft & Hub Separation: Billet One-Piece Overdrive Shaft & Hub
One the stock 68RFE transmissions, the overdrive clutch shaft and input clutch hub have a two-piece design that's then friction-welded together into a single component. Unfortunately, that weld creates a massive weak point that is prone to failure when you start stacking high levels of power onto your Ram. Since the Stage 3 68RFE is meant to handle big power and aggressive applications, we swap the welded OEM overdrive clutch hub with a one-piece billet steel overdrive shaft and hub to eliminate that point of failure. These overdrive hub and shaft combinations are made out of solid billet steel that's then CNC machined and drilled with the proper oiling holes to ensure proper lubrication of the overdrive clutches. The one-piece design completely eliminates the failure-prone friction weld for improved reliability, while the billet steel construction makes the whole assembly less likely to crack along the oiling holes.Keeping the Input Clutches in Place: Billet Input Clutch Hub
The input clutches do a lot of work as your Ram shifts up and down through its gear ranges, and the input clutch hub takes a lot of abuse. That abuse only gets worse when you start to add a ton of power to your Ram 6.7L Cummins build. The factory hub can suffer from cracking, warping, or even outright failure when put under enough strain, which is why we here at Tier One jump up to a billet input hub in our Stage 3 48RE transmissions. These hubs are made out of billet steel and are much more capable of handling the strain of big power Ram builds and the type of fast and hard shifting that your truck needs when putting down horsepower or towing extremely heavy loads.Improving Clutch Count & Clutch Reliability: Billet Inner & Outer Clutch Drums
The clutches deep inside the 68RFE are absolutely critical when it comes to the 68RFE's basic functions, and they're often a huge point of failure that can leave your Ram build dead on the side of the road. Granted, some of the issue is with the stock valve body not supplying enough line pressure for proper engagement or lubrication, but if you're going for pretty high levels of power, you're going to need not only more clutches to handle the load, but clutch drums that won't warp or gouge as the clutches operate. For our Stage 3 68RFE transmissions, we here at Tier One include both billet inner and outer clutch drums to give our Stage 3s the power-handling they need for your hyper-aggressive Ram truck build. These billet clutch drums have much greater structural strength than the stock clutch drums and are also made out of harder materials than the stock cast steel drums which greatly reduces their chances of getting gouged by the clutches as they actuate. The stock clutch drums getting gouged can cause binding and a failure to properly engage under load, leading to clutch slippage and burn-up.Improved Case Rigidity & Gouging Resistance: Billet Center Support
The center support is critical for maintaining the integrity of the 68RFE's case and providing a solid mounting location for other critical transmission components. Unfortunately, the 68RFE's stock center support is made out of relatively soft cast aluminum that can struggle to hold up to high levels of power and extreme applications. Secondly, the stock center support has a tendency to get gouged by other transmission components as they move, even if it's getting proper lubrication from a high-pressure valve body. For our Stage 3 68RFE transmission, we here at Tier One include a billet center support that provides the strength and rigidity the transmission needs to survive extremely high power Ram builds and tough driving both on and off the road. These 68RFE billet center supports are also far less likely to get gouged or damaged by other moving transmission components, keeping your truck's transmission reliable.Extra Piston Reliability & Power-Holding: Billet 2C and 4C Pistons
The pistons that are responsible for actuating your 68RFE's clutch packs are critical for your transmission's operation. Unfortunately, the stock 2C and 4C pistons aren't the strongest things in the world, and they have the tendency to crack or even break in two when put under a high enough load. Tier One includes both a billet 2C and billet 4C piston in every 68RFE transmission build. These pistons are made out of CNC machined billet steel that allows them to handle huge levels of horsepower and torque and survive engaging the 4C and 2C clutches without letting you or your 6.7L Cummins Ram down.The Hidden 68RFE Killer: Upgraded Rollerized Sprag
The stock low/reverse sprag is a well-known failure point in the 68RFEs. The OEM low/reverse sprag features a mix of metal and plastic components that cause it to struggle at even factory horsepower and torque levels. The really bad news is that a sprag failure is often catastrophic for your Ram's transmission, sending bits of metal and other material all over the place and potentially wrecking other components. That's why we here at Tier One use an upgraded rollerized sprag for our Stage 3 68RFE transmissions that features an all-metal construction with rollers that can withstand the huge forces of big-power Ram truck builds without letting you or your 6.7L Cummins down.Preventing Walk: Billet 4C Snap Ring Retainer
4C snap ring walkout has been a killer of many 68RFE transmissions, and while adding a billet center support does help with some movement, the real issue is the 4C snap ring retainer. The stock retainer is made of fairly soft materials that can fail and allow both the 4C snap ring and overdrive clutch hub to walk and possibly fail in spectacular ways. While a small component, the 4C retainer can have big consequences if it fails, which is why we here at Tier One install a billet 4C snap retainer and make the necessary modifications to ensure nothing walks out and causes you and your 68RFE serious issues.More Fluid and Less Heat: 68RFE Cast Aluminum Deep Transmission Pan
While the stock stamped steel transmission pan may do the job of holding in your 68RFE's transmission fluid, it also doesn't do your Ram 6.7L Cummins any favors. The stock transmission pan doesn't come with a drain plug which makes changing your Ram's transmission fluid and filter a giant pain in the neck. The stock pan also doesn't provide much in the way of improved cooling or more capacity, so upgrading only makes sense. Tier One installs a 68RFE deep transmission pan on each of our Stage 3 68RFE transmissions, and our deep transmission pan of choice is the PPE 68RFE Cast Aluminum Transmission Pan. PPE's pan is made out of A356 cast aluminum which is more rigid than the stock stamped steel transmission pan while also dissipating heat more effectively than the stock pan. Each pan features a deep design and holds 3 more quarts of fluid than stock which helps improve lubrication and serves as a heat sink to further improve cooling.