68RFE Valve Body • Problems & Solutions

68RFE Valve Body • Problems & Solutions

Next Gen Drivetrain Research & DevelopmentAugust 25, 20201 comment

Introduction to the 68RFE Valve Body:

     Let's get straight to the chase. The 68RFE Transmission’s Valve Body is inundated with problems, with nearly every component of it being prone to extreme failure. This is the part of the transmission that controls where all of the fluid travels to, to apply certain clutch packs and henceforth activate gears.

     For example, when you move your shift lever from park, to reverse, an oil circuit is opened by the manual valve in this valve body (which is connected to the shift lever) that directs oil to the L/R clutch pack, and the reverse clutch pack, putting the transmission in reverse.

68RFE Check Ball Locations

     The 68RFE has changed multiple times in it’s lifespan, and the lineage is as follows:

Gen 1 - 2007.5 to 2010 (7 Check Balls, known as the most problematic 68RFE’s. The Valve Bodies and Pumps are made of incredibly soft metal and have a fraction the lifespan. White Solenoid Pack.)

Gen 2 - 2011 to 2018 (5 Check Balls, Grey Solenoid Pack, but can be replaced with White.)

Gen 3 - 2019+ (Blue Solenoid Pack, can ONLY be replaced with Blue OEM Solenoid Pack)

Tip: For our DIY inclined customers who are looking for a no-machining, 100% drop-in, All-In-One 68RFE valve body solution kit, our best-selling Bulletproof68 kit can be found here:

>>> 68RFE “Bulletproof68” Kit (Deluxe)



Problem #1 - The Accumulation System

     The accumulator pistons are the part of the valve body that absorbs the shock that would otherwise be applied directly to a clutch pack. You can think of these as a shock absorber for a gear shift. Without accumulation in place, every gear would bang very aggressively and clutch application timing would be poor.

     The 68RFE Transmission’s accumulator pistons are dismally low quality; made of low quality plastic. They have 2 seals that are extremely loose and allow an extreme and unsafe amount of venting. Accumulator pistons are supposed to leak, they’re a controlled vent, but the factory pistons vent excessively which forces the clutch to suffer from less apply pressure.

     The solution to this is a quality, billet aluminum set of pistons with added seals of tighter tolerance, endorsing quality shift timing and behavior as well as predictable driving dynamics and increased torque capacity.

68RFE Valve Body Accumulator Piston

Problem #2 - The Accumulator Backing Plate

     The 68RFE Valve Body accumulator backing plate is the component that bolts to the valve body and holds the accumulation pistons in place. The pistons have springs between them and the plate, creating the “shock absorber” dynamic. In analogical comparison to a motor, this would be like a girdle. It’s designed to bolt somewhere and never move. Unfortunately, it is unable to do this efficiently.

     It often blows off from flexion due to being an incredibly weak and soft metal; a child could bend it by hand effortlessly. Increased line pressure from TCM tuning or pressure boxes only proliferate this failure. The solution is a steel, high quality backing plate that simply won’t fail. The issue here is not design, it’s part quality.

68RFE Valve Body Failed Accumulator Plate

Problem #3 - The Solenoid Switch Valve

     One of the less talked about subjects is the solenoid switch valve, often in acronym format as SSV. This is the biggest crossleak in the 68RFE Transmission, and infamously, is the one that causes most overdrive failures and P0871 codes. In short, this valve is very coarse in nature and causes bore wear quickly.

     When this happens, they will cause oil to leak out of overdrive when it’s needed most, decreasing torque capacity and catalyzing a catastrophic failure of the overdrive clutch pack. This valve is also a strong catalyst of a form of wear common in compressed hot oil applications known as “Galvanic Corrosion.” This is a form of wear where two metals corrode at their point of physical contact.

     The solution here is to machine this bore in totality and just simply start from a blank slate; replacing it with an upgraded valve designed not to fail. In fact, our 68RFE Research & Development Program has allowed us to apply this technological understanding to engineering a stronger, safer and faster 68RFE. You can see our hard work and dedication to manufacturing unique and high qualify products for this transmission here:

>>> 68RFE Transmissions, Rebuild Kits, Valve Bodies & Parts

     This is where it gets tricky and the egg-heads start to come out. The factory valve is made of a metallic compound that is heavy with elements like Nickel (Ni) and Iron (Fe). Though Iron generally won’t hurt too much, Nickel and Aluminum (Al, the material of the bore) generally don’t get along. We identified the solution for this using the scientific method, and it’s very simple.

     Imagine trying to scratch a diamond with a pencil. The pencil is not hard enough to hurt the diamond, and the diamond is not coarse enough to hurt the pencil. Weird combination, but one that certainly won’t be hurting the other anytime soon. This is basic physics, and we use this logic when strategizing how to correct this part of the valve body. The result was the implementation of completely and totally redesigned steel valve, axial support spring and steel ground end plugs, all sporting an ultra-protective anodization to prevent future bore wear as well.

     In fact, every ~100 valve bodies, we select one for additional testing. We test this leak point after cycling this valve thousands of times in properly filtered oil, replicating years of use and abuse in a well maintained truck. We do this because we wholly expect our products to be abused and neglected, and engineer and manufacture them accordingly; not to break.

     We have discovered that even after this aggressive form of testing, the valve holds no measurably lower amount of vacuum pressure than before. The data there within justifies the conclusion that this solution has no rational lifespan, and is to be considered a long term solution to this style of crossleak. This means, from an engineering perspective, that this choice of SSV solution is superior in the interest of longevity, reliability, practicality and performance.

     This technology is unfortunately not available without machine work and is only available in our proprietary transmissions and valve bodies, though our Bulletproof68 kit does offer an anti-seize solution for this that is excellent for presently healthy valve bodies.


68RFE Valve Body Solenoid Switch Valve

Problem #4 - The Solenoid Pack

     In association with this, is the solenoid pack itself. The solenoid pack is the “box” of electronics that bolts to the valve body and controls the activation of clutches inside the transmission in conjunction with the TCM’s adaptive shift logic using “Boolean” style logic and logic gates in the internal pressure manifold of the solenoid pack to comply with TCM issued commands.

     Simply put, it’s the electronic part of the valve body with the solenoids, it fails a lot over time, replace it with a brand new OEM unit every rebuild, do not use an aftermarket solenoid pack! They are far more prone to failure. Solenoid packs with a “Black” rubber weather ring around them are aftermarket. We offer brand new OEM solenoid packs here:

>>> 68RFE Updated Mopar OEM Solenoid Pack (All Years)


68RFE Solenoid Pack
Problem #5 - The Separator Plate

     A further failure is the separator plate itself. The separator plate is the component that functions as a gasket the upper and lower half of the valve body assembly. This would be like a head gasket in the motor, it is a steel plate with holes laser cut into it to perpetuate oil circuitry in the valve body.

     The failure here is two-fold; firstly, that the separator plate is too thin and just simply leaks, and secondarily, that the oil circuitry is just not efficient and an updated design is a critical opportunity to enhance how this transmission behaves. Aftermarket plates should also be thicker as the thickness of this plate is not nearly as fussy as a head gasket job. (PTV clearance, etc.) Below pictured is a "bonded" style aftermarket separator plate.

68RFE Valve Body Bonded Separator Plate

 Problem #6 - The Low/Reverse Switch Valve

      Yet another failure to the 68RFE Valve Body is the L/R switch valve, the L/R switch valve is a small valve the size of a pea that controls the application of the L/R clutch pack when directed by the L/R oil solenoid. This valve rarely fails, but when it does, it either crossleaks immensely causing potential P0736 (Incorrect gear ratio reverse) or P0731 (Incorrect gear ratio first gear) codes.

     The solution here is a precision machined aluminum valve that features cleaning lands to prevent bore wear over time. The L/R switch valve of our complete transmissions and valve bodies are designed with a self-cleaning switch valve. This valve has multiple additional cleaning lands in place that are designed to collect granulations and clutch material and displace them from the valve bore to be re-filtered later. 

Problem #7 - The Lower Valve Body/Channel Plate

     Lastly, and not least, the transfer plate of the transmission is the lower half of the valve body. It simply directs oil about the valve body in a convoluted fashion. There are two problems with this plate, both design and quality. The design is inefficient because it endorses limitation to potential line pressure capabilities by forcing oil directly to the PRV bore of the pump for relief.

     The quality concern is that this is the softest metal used anywhere in the 68RFE Transmission. It is incredibly soft and will flex aggressively over time. For customers considering products like our Bulletproof68 kit, a billet channel plate is a must if you plan to run added line pressure, even for reliability reasons.

     The solution here, as pictured above, is very complex, one must precision machine this plate to perfection on a CNC machine, later being cleaned of excess metal waste and then flattened using a laser. Further, one must modify the oil circuitry by hand to create a relief before the PRV bore enabling higher pressure without modifying the pump, whilst maintaining proper oil geometry across the rest of the unit. Our Formula One Billet Channel Plate is a direct solution for these known ailments.

     Optimally, aftermarket plates like our’s often come with modifications pre-made and are manufactured from high quality billet materials that are design to be totalitarian and life-long solutions that never fail. These are called “Billet Channel Plates” and are critical. Our flagship Formula One Valve Body is warrantied for life because of this specific modification, tandem with our NeverLeak valves. It encompasses all of these solutions in one ready to bolt in package. One can read more here:

>>> 68RFE “Formula One” Billet Valve Body

     There beyond, pictured below is an example of a billet 68RFE valve body channel plate.


68RFE Billet Channel Plate
Conclusion:

     To conclude, the 68RFE Valve Body is undeniably the largest failure point in the entire unit. Above, we’ve assessed why this occurs from a technical perspective and presented informative data and content to educate our consumers on the failures and solutions needed to modify and upgrade a quality 68RFE Transmission. For further education, we encourage you to call us Monday through Friday and talk to one of our 68RFE experts!

Comments (1)

John A Walsh on October 05, 2020

68rfe transmission 2008.6.7 4×4.it only had first and second gear.

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