To keep all equal, we held the truck at 2000RPM, 3rd gear, put between 200-240 wheel horsepower of load on it and held that for 1 minute intervals with brief cooldown periods in between. To best replicate the fault, we observed the conditions that caused a P0871 to set in a late model truck (that already had the anodized valve body) and recreated those on the dyno. Our sensors are wired into a high speed data logger that is also tapped into engine/TCM sensors. Analog gauges with rubber hose are far too inaccurate for this type of testing and length of rubber hose acts as an accumulator or buffer to the readings. Here we have modified a transmission oil pan to accept bulkhead fittings, installed pressure transducers (sensors) and connected very small nylon lines to the valve body to get accurate and fast response pressure readings. 1-The Solenoid Shift Valve (SSV) and 2-The Valve Body Separator Plate. This means by the time you're setting P0871s, you've already been dragging the OD clutches.Ĭertainly there could be minor leaks from many areas, but our exhaustive testing shows there are only two areas we need to concentrate on to correct this leak. Our experimentation shows this switch triggers at 16PSI, this just so happens to be right around the pressure required to apply the OD clutches (air check this if you don't believe us). This code is triggered when the pressure switch in the solenoid pack detects pressure in the circuit when it shouldn't be. Leaks into the OD circuit will cause the annoying P0871 code (set in 2nd or 3rd gear) but are also partially responsible for the burnt OD clutches we see on a daily basis. The caveat of increased line pressure is increased cross leaks, so it is important for us to correct these leaks when making a performance transmission. We, like most others, increase line pressure in our 68RFE transmissions to increase clutch holding capability. The most common cross leak observed with 68RFE transmissions is leakage into the overdrive (OD) hydraulic circuit this is in fact the only chronic cross leak area we see on 68RFEs. It is tribal knowledge among transmission builders that valve bores need to be inspected or vacuum checked and repaired and that flat surfaces need flat sanding to reduce cross leaks, but this "old wisdom" does not always result in a "fix" for newer transmissions. One of those is cross leaks in the valve body. Part One: The Valve BodyĪlthough cited as the weak link in the 2007 to present 6.7 Ram trucks, the 68RFE transmission can be a decent unit if you can correct some of its shortcomings. I cant believe the difference it made! Whoever you get your EFILive from (one of the reputable places of your choice, I like my Firepunk and its a great deal as well!), I am sure you will be nothing short of impressed.Trials and Tribulations of the 68RFE. It just ramps up smoothly but quickly.Īll you need for these trucks is some EFILive tuning and a built transmission and you have a helluva vehicle. It is easy to dial up a little extra pedal to get the power, whereas on the smarty, it kinda started to go and then turbo spooled and then it shot forward. Yes their CSP5 switch is the socal diesel pass through switch (thats not on their website).Īs for spooling times and how nice the power comes on? Well needless to say spool didnt change much if any at all (no changes to manifold or turbo obviously). but needless to say I probably wont even need to use the race tune because its already just ridiculously fast. I will try the towing tune on my way home from work. I didnt even try the towing tune which I assume is the one that is a little more tame than the fuel economy tune (I am not aware of any real changes between these other than RP per my CTS2). 5 OTF tuning options are something you dont think you will need but something you will definitely use. This tuning is really clean, much cleaner than the smarty JR it had.Īnd the CSP5 Switch? Its everything you imagine it is. The highest setting I turned it to was 'street' and that put a huge ear to ear grin on my face. Well, after getting my EFILive into my truck last night, I drove it to work this morning and all I can say is WOW.
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