The valve body is like the brain of the transmission. It is the single most important item in the transmission. Here at SunCoast, we take a very scientific approach to how we calibrate these units. We start with addressing the accumulator cover plate. It has been shown time and time again that these factory side plates are prone to deflection due to the fact they are made with inferior steel, and a bit thinner than desired. If you start driving line pressure even higher, you will see this issue with deflection become even more prevalent. When this deflection occurs, it often times will cause the screws to loosen, and in some instances even break. SunCoast replaces the factory plate with a thicker, reinforced plate that adds 3 additional holes to allow for additional, stronger mounting screws to keep flex to a minimum. This new accumulator cover plate is standard on all SunCoast 68RFE builds.
SunCoast continues the improvements on the valve body circuit by replacing each solenoid pack with a brand new factory OE Mopar solenoid pack. This may be incredibly expensive, but we feel it is an absolute must. While the reasons may be obvious to some, allow me to explain it to you. Every other builder either uses the factory solenoid pack again, or a remanufactured one. Here at SunCoast, this is unacceptable and here is why: It is well documented that the solenoid pack has numerous fail issues. If you have a core that you are building from, more than likely it is there as a core because it failed. When failure occurs, debris, in the way of metals, clutch material, and other contaminants are circulated throughout the transmission.
That debris is almost certain to have made its way into the solenoids. This contamination in the solenoids now remains there. So now we take this new, freshly built transmission and introduce the contaminants from the failure into our new unit. Those contaminants can, and will, affect the spray pattern and flow of these solenoids. In the early days, we took the liberty of purchasing a solenoid flow tester to verify the integrity of these solenoids. What we found is that the failure rate was in excess of 60% due to contaminants. Of that 60%, about 10% could be run through the flow tester with a special solvent to clean them enough to restore the spray pattern and flow rate. Our competition may make the argument that they spent the $10,000 + to check and verify these solenoids and clean them, but the only issue with this is that you are still going to have a significant failure rate. SunCoast, as well as Chrysler, has documented that the factory boards on these solenoid packs flex, causing false pressure switch codes. So even if you spent the 5+ hours to restore the flow rate and spray pattern you still have a fatigued board. This could very well cause false codes and drivability issues. SunCoast corrects this by throwing the factory solenoid pack in the trash and replacing it with a new factory unit from Mopar. SunCoast also installs a custom made solenoid spacer-block to correct the flexing issue. Some may tell you that this is overkill, and unnecessary, but we believe it is our duty to ensure that our customers get exactly what they deserve. No corners cut, no shortcuts taken.
Another area of concern in the factory valve body is the issue with the factory solenoid switch valve. These factory pieces allow cross-leaking and continually cause burnt 4C and Overdrive clutches. Very often, it causes the plugs to cock and hang up in the bore. This will result in a failsafe (limp mode), various codes, bind-ups, and burnt TCC clutches. Customers will often complain of the engine stalling, or loss of fuel economy, due to no lock-up. On every one of our SunCoast valve bodies we correct this by replacing the factory solenoid switch valve with a new, custom designed valve made with annular grooves to help center the valve and plugs in the bore to prevent future side-load wear. This special valve is also hard-coat anodized to prevent premature wear. We also have special o-ringed end bore plugs that have been redesigned to ensure cocking can no longer occur. Finally, the next problematic area we correct is the issue with the factory Overdrive/Underdrive accumulator piston. You will see others attempting to shim these accumulators, trying to correct stroke issues, and they use recalibrated springs to correct the cold driving 1-2 shudder, excessive CVI's, slide shift, etc. The fact that it is plastic doesn't help either. There are companies even making sleeves to try and attempt to fix the bore cross leaking. Our fix is to redesign it. SunCoast uses a custom billet accumulator piston with additional sealing rings, made in-house. This new custom billet overdrive/underdrive piston not only corrects cross-leaking, but it also changes the stroke of the accumulator, allowing much quicker shifts than could be achieved otherwise. This also extends the life of the overdrive/underdrive clutches. Is a billet, custom CNC'd accumulator piston really needed? Well if youre SunCoast, the answer is obvious and it is in every one of our valve bodies. What does your builder do?