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42LRE Transmission ( Auto ) aux cooler and Temp sensor mod

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  • 42LRE Transmission ( Auto ) aux cooler and Temp sensor mod

    This guide will show you how to install an aux cooler and temperature sensor for your transmission.
    I used a Derale 19 row plate and fin cooler:
    Total price around $50
    Temperature sensor came with a transmission gauge kit from GlowShift Gauges:
    You can use any gauge setup you wish
    I used a Fuel filter line adapter to put the temp sensor inline:
    You need to look for a 3/8 Barb with a 1/8 NPT hole for the sensor.
    You will NEED a 1/8 NPT extension to get it to fit.
    $_57 (1).jpg
    You must use pipe tape to seal it together.

    Photo Apr 25, 00 21 51.jpg
    You need to plumb the temp sensor in the hot side before the radiator - also a good time to install a magnetic trans filter - check out the other thread
    Photo Apr 25, 13 57 59.jpg

    Start by removing or loosening your radiator to make room to slip the cooler into your front behind the grill.
    Photo Apr 25, 12 57 04.jpg
    Use stainless steel cable ties to secure it 75% up on the grill support bars - USE AS MANY AS YOU HAVE HOLES IN YOUR COOLER!!
    I have plastic ones showing in this as it was temporary until my stainless ones arrived.
    also my radiator was removed to better show this
    Photo Apr 25, 12 51 11.jpg
    Mount the cooler with both input and output barbs pointing to the drivers side of the vehicle.
    Now route your transmission hose from the output on the drivers side of the bottom of the radiator to the bottom of the cooler.
    Connect the top of the cooler to the return line of the transmission.
    Be sure to cable tie the lines so they do not rub or kink.

    Pull the emergency brake, chock the wheels - start the vehicle, put it in drive and then let the transmission pump all the air out of the cooler
    Check for leaks then add ATF+4 until the levels read correct.

    Enjoy a cooler transmission, better shifting and being able to watch the temperature!
    2003 TJ X - Light Metallic Khaki and Black "Blackout Special" on 33x12.5 Wrangler MT/R Kevlar Tires
    M101 CDN2 Trailer on 33x12.5 Wrangler MT/R Kevlar Tires

    More mods than can fit in a signature ;-)

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