Results 1 to 7 of 7

Thread: Replace 65RFE with 66RFE - 2013 Ram 1500 2WD

  1. #1
    Potential Tuner
    Join Date
    Apr 2011
    Posts
    6

    Replace 65RFE with 66RFE - 2013 Ram 1500 2WD

    I have a 2013 Ram 1500 2WD Sport that I bought new in 2013 and has around 166K mi on the transmission now. I wish I would've waited 6 months for an 8-speed but I needed a new vehicle and no dealers had any 8-speeds in stock early 2013 MY.

    Background: Truck has been daily for the past 8 years and has been a great truck, all things considered. Last year I started adding mods, out of necessity and once started, I couldn't stop - been able to hold off several years. I had a Vararam from a few years ago since the factory clips on the stock airbox broke but was stock otherwise. I had lived with the exhaust manifold leaks for a while but finally repaired those and while I was in there, added some ARH 1 3/4" LTs with catted y-pipe. I had a hemifever tune on it, added an ARH cat-back due to some rattles in the factory exhaust, etc. This last summer I had a tick develop and oil life reduce drastically - ended up having a seized lifter roller. Instead of simply repairing the top end, the engine was tired and the rings were a bit loose, I opted for MMX's 392 with mild NSR cam, ported 6.4 manifold, etc. The local tuner used HP Tuners but didn't really tune it that well - they are used to the cars and the tuning on these trucks (GPEC2) is very different (?) but I have access and ability to edit everything. While the engine was out, went ahead and put in a ~3200 stall. I knew the transmissions wouldn't last long in this configuration but I figured if I babied it I could at least get a year or so out of it, but I only have 3 weeks in it with the new engine, making about 420 at the wheels (heavy 22" hellcat replicas in 3rd gear) and I go into limp mode anytime I need to get into OD gears with the dreaded P0734/P0735 codes.

    I would love to attempt an 8-speed swap (or any custom setup) but we just sold our house this past summer and are in the process of buying land and building so we are in a rental and I cannot attempt anything too crazy until I have a shop again.

    I don't like the idea of putting another 65RFE back in due to the weakness of the OD clutches and the special driving requirements needed to make it last (no WOT downshifts). I also hate the gear spacing of the 65RFE and I am looking at different options. I have read about PCM issues when trying to use other transmissions like the 66RFE but with what I see in HP tuners (see attached screenshot), 66RFE is a selectable transmission from the Trans Type drop-down and it would appear that the trans gear ratios are editable? What am I missing that makes this swap undesirable - is there more to it than selecting the trans type, updating the gears, and enabling the 2-3 shift, from the PCM perspective? I assume I would need to take it a transmission shop for the relearn process or something...?

    I have been researching the internet for months on transmission swap ideas, any guidance or help is appreciated! I am still learning all of the jargon and abbreviations within HP Tuners - I apologize in advance.
    Attached Images Attached Images

  2. #2
    Advanced Tuner
    Join Date
    May 2018
    Location
    Germany
    Posts
    275
    yes, the rfe65 is crap.
    I think about changing but for 4wd theres more than a simple swap and Software.
    Higher rpm, 3rd enable, other shift Points, no shift reduction and some tcc settings will help a Little bit.

    idles.hpt

  3. #3
    Potential Tuner
    Join Date
    Apr 2011
    Posts
    6
    But is it as easy as adjusting some tuning parameters for the 2WD crowd or will it not work? When I see posts in the past about adjusting the PCM for various transmissions, they always say it can?t be done and it isn?t supported and since I am new to HP Tuners, I don?t know if these options I?m seeing are new (making it possible) or not.

  4. #4
    Advanced Tuner
    Join Date
    May 2018
    Location
    Germany
    Posts
    275
    there is an option to change the tranny in the soft .
    the drop down menue shows the 66.
    so you have to change the ratios and look at a 66 file to be sure that the tcc settings will work.
    I think it may work.

  5. #5
    Potential Tuner
    Join Date
    Apr 2011
    Posts
    6
    I think I?m going to give it a try and see what happens

  6. #6
    Quote Originally Posted by 1SLwLS1 View Post
    I think I?m going to give it a try and see what happens
    Did You Ever Put A 66RFE In Your 65RFE Vehicle. Was It As Simple At Changing Gear Ratio Values To 66 And Selecting 66RFE And 2Prime Enable? I've Got A 545RFE Jeep That I'd Like To Swap To The 66RFE And Built It Once My 545 Bites The Dust. (Or Build My 545 With 66RFE Geartrain But Would Probably Be Cheaper To Just Get A Complete Used 66)

  7. #7
    Potential Tuner
    Join Date
    Apr 2011
    Posts
    6
    So I tried but the truck didn't recognize it; I was told that the solenoid pack is a likely culprit but didn't want to dump more money into that experiment. Oddly enough, when I ended up rebuilding the stock 65RFE, it also had solenoid pack issues (different builder used wrong solenoid pack).

    I ended up going with an 8 speed swap (still in process) and will be using a harness from Sound German Automotive and his works by essentially telling the factory PCM that it has a manual transmission (like I attempted with the 66RFE) and doesn't process any signals received from the transmission and uses the factory 8HP TCM. So I still think in theory, it should've worked, but I may've had a bad solenoid pack.