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  • Step-by-Step 4R70W Automatic Transmission Installation

    ****ATTENTION potential 4R70W installer**** If you intend to reference this thread in accomplishing your installation, I STRONGLY urge you to carefully read through the ENTIRE writeup. Modifications were made along the way so everything is not necessarily is perfect operational order.

    This article will guide you, step by step, through the installation of a 4R70W automatic transmission into a Early Bronco with a C4 automatic, D20 J-shift transfer case, and 302 engine.

    I used info in the following threads to gain general information regarding different aspects of the swap.






    The C4 has served me well but with the 35" tires, 4.56 gears and my personal requirement to make this rig drive to events, I was forced to install something with overdrive. With the C4, my RPM sat around 3,000 @ 60MPH which was unacceptable to me. I have no desire to travel faster than 60 because this huge rolling brick becomes a massive drag device and MPG go even further down the toilet. I prefer to see my RPM cruise around 2300 RPM and with the 0.7 gear ratio of the 4R70W, I was able to achieve that goal.

    Below is my list of parts which I have added as of the conclusion of the project which totaled $1,980.00

    4R70W-junkyard-'99 AWD V8 Mountaineer -$320 + $30 core
    starter-junkyard-'99 AWD V8 Mountaineer-$ Included w/ transmission
    converter-junkyard-'99 AWD V8 Mountaineer-$ Included w/ transmission
    flexplate-junkyard-'99 AWD V8 Mountaineer-$ Included w/ transmission
    ZF crossmember-BC Broncos-ZF-$125.99
    ZF adapter-BC Broncos-50-4303-$441
    harness-Baumann-HPF2 or HPF2A-$ Included w/ controller
    shift cable-Lokar-ACA-1808-$52
    Lokar Dipstick -$$105.90
    JB Fab Twin Sticks-$149.03
    Aux cooler lines-$23.99
    Adapter seal 471950-$18.36
    Misc fitting, bolts, and other crap-$59.61
    14 quarts of trans fluid and trans filter:$90.00

    Got the 4R70W from a 1999 Mountaineer AWD (also referred to a 4WD or 4x4) 5.0 with 100K miles from a local salvage yard.

    Click here to continue to the rest of the installation...
    This article was originally published in forum thread: Step-by-Step 4R70W Automatic Transmission Installation started by chuzie View original post