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falconbrother's avatar
falconbrother
Explorer II
Mar 28, 2017

UR opinion, extra transmission cooler..

I pulled the grill on my (5.3 Liter, 4L60e transmission) Suburban to install an oil cooler and there's a factory oil cooler mounted behind the grill already. I traced the line from the return side of the radiator to the cooler then to the transmission. It's definitely a secondary transmission oil cooler. I have considered installing the the one I bought along with the factory secondary but, now think I probably don't need it. Any opinions?
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  • falconbrother's avatar
    falconbrother
    Explorer II
    Mar 28, 2017
    bgum wrote:
    Sure it's not a AC cooler?


    It's definitely a factory auxiliary transmission oil cooler. The condenser is a great big thing and, this vehicle has a power steering oil cooler as well, OEM. I think I will leave it alone. The transmission runs cool, as far as I can tell, no problems with it and I keep fresh Dex-6 in it. I ground down the factory drain plug, that rounds off and works for no one, and welded an 11/16 nut to the plug. Now doing a simple drain and fill of the transmission takes 5 minutes.
  • Terryallan's avatar
    Terryallan
    Explorer II
    Mar 28, 2017
    Nope you don't need it. And to be honest. You want the transmission running at temp. Too cool can be a problem. could keep the trany from changing gears correctly. They change differently before they warm up, at least mine does. Won't go into OD before it warms up.
  • agesilaus's avatar
    agesilaus
    Explorer III
    Mar 28, 2017
    Has your trans fluid been running hot? If not then the engineer's rule applies: "if it ain't broke don't fix it!

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