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Tranny Cooler

Discussion in 'Intermediate CJ-5/6/7/8' started by Lockman, Jan 11, 2022.

  1. Jan 11, 2022
    Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Silver Hill,...
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    Was wondering if anyone could give their opinion on a Tranny oil cooler for my '75 ? It's got a 4 speed auto. Last year , before Plow Season, I installed a Hayden 678 in my XJ . I never noticed any Temp difference, up or down, but I 'm sure it doesn't hurt anything .
    Thanks
    ....Richie
     
  2. Jan 11, 2022
    Jw60

    Jw60 Sitting up n buckled down. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Sedalia MO.
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    If you are going on trails, towing, plowing, or heavy on the foot n' whistle it is generally a good idea. They do have thermostatic valves which will keep it from overcooling.
     
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  3. Jan 15, 2022
    jeepdaddy2000

    jeepdaddy2000 Active Member

    Eagle Point oregon
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    I think the question is what are you using now? If you have your trans connected to a stock cooling coil in the radiator and you aren't towing or other heavy use then you should be fine. If you are taxing the trans then any aftermarket external cooler will work fine.
    IMHO, it's more important to monitor the fluid for color and smell. If it smells burnt or looks like cocoa cola, you might think about a service. You should be sure to do a complete flush about every 70K or so.
     
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  4. Jan 16, 2022
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
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    Sorry but if it smells or looks burnt or looks like cola damage is already being done. Transmission coolers are NOT all the same. They need to be matched to the vehicle and what it is used for. That’s why aftermarket coolers have btu ratings. Most suppliers/manufacturers have charts or resources to help one figure out what one needs. If the cooler is too large the transmission will not warm up enough to work correctly. If too small it will run too hot. hell, my ‘04 3/4 ton Suburban has a factory transmission temperature gauge in the instrument cluster. I wonder why?
     
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  5. Jan 16, 2022
    Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    X2 nick ,That's what I have gathered also. :study:
     
  6. Jan 16, 2022
    jeepdaddy2000

    jeepdaddy2000 Active Member

    Eagle Point oregon
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    Let me rewrite my post:
    You don't need a cooler unless you're taxing the transmission.
    If you do need one, most any will do. it's implied that it's the right size and installed properly.
    Maintenance is more important than a cooler.

    On a side note, very few automobiles or light trucks with either manual or automatic transmissions come stock with a transmission temperature gauge. Many newer computer controlled cars and trucks have sensors that throw an engine light and toss the rig into limp mode if the transmission overheats.
     
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  7. Jan 16, 2022
    68BuickV6

    68BuickV6 Well-Known Member

    Hesperia, CA.
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    Highly recommend something with a fan and a thermostat switch if you expect to work the trans hard. Did that on the 1210, absolutely worth the cost.
     
  8. Jan 16, 2022
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
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    you are talking modern vehicles yet this is an early CJ forum where vehicles don’t have those. My example was simply to show the importance of trans temperature. The factory felt it was important enough to add a gauge to a vehicle used for towing yet also had the self protection devices you describe to help it keep from getting to that point. Wonder why? And if the vehicle hits limp mode damage is already beginning. These older vehicles with autos most likely have not been retrofitted with those systems. Again, coolers are not all the same. Coolers and maintenance go hand in hand. Ask any good transmission builder what kills autos more than anything. Overheating. I have talked to many, many auto builders and they all have told me the exact same thing. These are folks that build overdrive autos to handle huge big block V-8 power successfully.
     
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  9. Jan 17, 2022
    Jw60

    Jw60 Sitting up n buckled down. 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Nick what is your view on the thermostatic bypass? Seems you could run a larger cooler without issue of overcooling.
     
  10. Jan 17, 2022
    jeepdaddy2000

    jeepdaddy2000 Active Member

    Eagle Point oregon
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    Sorry, you were the one who brought up a modern car (04 burb)

    Virtually no pre computer cars or trucks came stock with a temp gauge. I've owned/driven numerous trucks over the years and the only one I've experienced with a stock gauge is the Tundra (I'm sure I've missed one or two others somewhere). I've needed to add one on all of my diesel tow rigs and those additions were a necessary upgrade when doing engine modifications.

    I agree heat is the biggest destroyer of auto transmissions in pulling rigs. In rigs that don't get taxed, maintenance is more important than a cooler. As you stated, this is a Jeep forum so that statement should fit.

    Are we arguing over points we agree on?
     
  11. Jan 17, 2022
    termin8ed

    termin8ed I didn't do it Staff Member

    Mason, MI
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    Agree to disagree...:contract:

    Does it have any cooler at the moment?
    It will at least need an integral radiator/trans cooler, or external cooler. If it doesn't have one at all I would look into getting one. Nick is right in that it needs to be sized correctly.

    The ones I'm familiar with let either no, or a little fluid to bypass depending what was engineered. Once the fluid gets warmed up they open up and let fluid thru the cooler. And even then it's usually when the engine is reved up and not at idle. They are a pain to do a fluid flush with the machines that hook into the cooler lines.
    In a modern car they do everything they can to get the engine and trans up to operating temps for emissions control. On an older vehicle not sure if it would really make that much of a difference. Or one that your going to notice. If anything it will keep the trans on the hotter side
     
  12. Jan 19, 2022
    johneyboy03

    johneyboy03 The green beast

    Quebec, Canada
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    Betteer to have a one than not have one.

    As for temps...overcooling is not a real problem. Overheating is one.

    Rode my pick in a -20f situation and transmission stay in the low 40f.
     
  13. Jan 19, 2022
    timgr

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    I though the usual config is to put the aux cooler before the factory cooler in the radiator. Then the oil will warm up with the engine and any excess heat will be removed before it goes to the moderating factory cooler.
     
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  14. Jan 19, 2022
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
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    Usually the aux cooler goes in front of the radiator as it's the only location it would fit.
    Is it correct location?
    This gets argued about every time it comes up.
     
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  15. Jan 20, 2022
    johneyboy03

    johneyboy03 The green beast

    Quebec, Canada
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    Tranny cooler before engine cooler. Make sure you leave some space between the two so you wont have any heat transfert from one to the other.

    Power steering cooler on left side and tranny on right side, Has for tranny since i'm a little hard wheeler i went to a overkill one.

    189112307_590257195213560_3247733259954562815_n (1).jpg


    191687699_436467550877948_881631359253045221_n.jpg
     
  16. Jan 20, 2022
    Lockman

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    Your Tranny cooler side is Huge. Did you say "Overkill " ?. Thanks.
     
  17. Jan 20, 2022
    68BuickV6

    68BuickV6 Well-Known Member

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    That thing is massive! Do you have info on it?
     
  18. Jan 21, 2022
    johneyboy03

    johneyboy03 The green beast

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    https://derale.com/product-footer/f...ate2013-10-28-09-53-271154803941/54012-detail

    That's their biggest cooler derale is making. But as said i been one the overkill side since i'm a little hard on gaz pedal, especialy on the snow. I have burn out a complete rebuit th350 after its second ride due to liquid getting overheating. Now it not a problem anymore.
     
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  19. Jan 21, 2022
    johneyboy03

    johneyboy03 The green beast

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    Cost me a 1500$ freshly rebuilt th350 on second trail....i dont want that to happen again :p
     
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  20. Jan 21, 2022
    68BuickV6

    68BuickV6 Well-Known Member

    Hesperia, CA.
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    That's really nice. I put a Derale 13700 in my fiance's 1210 because I wanted the fan, and couldn't go much wider without getting close to the core support.

    If anything ever happens, I'm upgrading to yours.
     
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