Transmission Cooler Recommendation.

Discussion in 'The "Juice Box"' started by LARRY70GS, Jul 28, 2015.

  1. DasRottweiler

    DasRottweiler -BuickAddict-

    Heading back to the transmission ends of the lines, can it be confirmed that the adapter is 1/4 20 to6an for the larger TH400 fitting? Also is it not a "no-no" to have inlet and outlet facing down on an aftermarket cooler? THANKS, Jim/Rott
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    The fittings I linked are the right ones.

    I don't see a problem with mounting the cooler with the inlet and outlet up or down. Gravity assists in one direction either way.:Do No:
  3. DasRottweiler

    DasRottweiler -BuickAddict-

    Thanks Larry, purchased and on the way.
    Using Aeroquip hoses and fittings to the bigger 11"11" B&M Supercooler. Stand alone w/o using radiator trans cooler. Gonna be enough? Jim/Rott
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I don't see why not. If you don't use the radiator cooler, it is possible to over cool the ATF in cold weather. I try to drive my car in the winter as long as the roads are clear of snow, ice, and salt.
  5. DasRottweiler

    DasRottweiler -BuickAddict-

    I will not be doing any winter driving here in NH. Too much sand n salt. Will allow for warmup time when it is cool/cold thou. Ty for your help and advice Larry. Jim/Rott
  6. deekster_caddy

    deekster_caddy Well-Known Member

    This thread keeps getting better and better! Thanks for the info about the flexplate!

    I would like to put a good sized cooler in my '73 LeSabre and will occasionally drive it in cold temperatures. Has anyone ever used an oil thermostat like this?

    or similar? (that's just the first one I found, not necessarily the one I would buy, just using as an example)

    I'm sometimes concerned that the cooler I need for hot weather driving and towing will make the trans too cool in the winter.

    (p.s. the '73 LeSabre is running Bob C's EFI 455 and about to be running his TH400 previously mentioned)

    -Derek C.
  7. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    If you run it through the radiator cooler also, you won't over cool the ATF. Are you getting Bob's switch pitch?
  8. deekster_caddy

    deekster_caddy Well-Known Member

    Yes. I'm running a switch pitch now, but not as good as the one from Bob's car. We will be installing that with the trans soon. It will run through the rad cooler.
    I believe it makes a difference which order it goes in - through the external cooler first, then the rad cooler or the other way around? (and is that from the top or bottom tube?) I would think it should go through the external cooler first, so it gets warmed to at least the temp of the radiator.
  9. 70Cat

    70Cat Well-Known Member

    I've used something like those on my Mercury Marauder. Most transmission shops will carry them for much less without AN fittings if don't want to run them.

    I jammed an F350 superduty trans cooler in the merc and the trans temp at the pan never got above 110. Once I put the thermostat in there it fixed the overcooling problem.
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    No, the fluid runs through the radiator cooler first, then the auxiliary cooler, then back to the transmission.
  11. deekster_caddy

    deekster_caddy Well-Known Member

    And - should the upper or lower tube be diverted to the aux cooler? Which is the source?
    (thanks Larry!)
  12. Ttype455

    Ttype455 Well-Known Member

    Im pretty sure the one out of the top of the radiator will goto the cooler.
  13. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Yes, Hot ATF exits the transmission via the bottom line. It enters the radiator cooler at the bottom, exits the radiator cooler at the top, and back to the transmission. The Ron Sessions THM400 book recommends the series installation for the auxiliary cooler. Top outlet of the radiator cooler goes to the auxiliary cooler, and then back to the transmission at the top.


  14. Ken Warner

    Ken Warner Stand-up Philosopher

    I've always wondered why the hot coolant enters the top of the radiator but hot transmission fluid starts at the bottom?
  15. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Did the Transmission swap on Saturday. I wanted to install the cooler in the same spot as my other one but the cross braces interfered. John suggested I mount it vertically to the center hood latch support. It gets air through the grill and the space above the licence plate and bumper. All the fittings went in leak free and we ran the hose through an existing hole on the frame. Came out great, and it doesn't leak.

    Transcooler1R.jpg TransCooler2R.jpg TransCooler3R.jpg
    Last edited: Jan 1, 2018
  16. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    We ended up using 2 washers between the converter and flex plate, we had plenty of room between the ARP bolts and the front cover of the converter.
  17. Jim Weise

    Jim Weise 1000+HP


    I have always wondered if the radiator trans fluid heat ex-changer really did anything useful. Most folks don't even know what they look like, I know I didn't until I started doing restos, and taking the factory radiators apart to get the right tanks on them..

    Here are a couple pictures..



    I remember thinking what a joke that was..

    I have seen a more substantial heat ex-changer in some aftermarket radiators. I recall one that was in one of my trucks, that when you took the cap off, all you saw was the heat exchanger.

    You could find out.. all it would take is an infra-red heat gun, two -6AN caps and a short line to connect the hoses together to by-pass the radiator radiator heat ex-changer.

    Pick a route in your area, and drive it from a cold car, with and without the radiator in series. Stop at a mid point and check your temps. You can check both the cooler, and the trans pan with the gun.

    It would be interesting information. I know the debate rages about series and stand alone, but I think most of those folks screaming about it have very little actual data to rely on.

  18. TexasJohn55

    TexasJohn55 Well-Known Member

    Install a permanent guage in the transmission pan, it will answer all questions about coolers and efficiency for your car.
  19. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I really don't need any more gauges in my car, it's kind of crowded already:grin: I ordered a temperature gun. I believe I can easily eliminate the radiator cooler so I may just do what you suggest Jim.
  20. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I really wanted to be sure about the cooler line pressure. I had a digital Cyberdyne gauge and sender laying around so I hooked it up. I took off both lines at the radiator cooler and used a union with a pressure tap so I could screw in the sender. I took it for a drive warming it up to operating temperatures. Pressures going down the road in high gear were about 30 or so. I got up on the converter some but the most I saw then and jumping on it were maybe 40 psi. I am going to leave it hooked up like that temporarily so I can monitor the pressures when I take it for a long drive. When I put it into manual 1 and 2, the pressures go up, highest I saw was 60 or so.

    Last edited: Aug 27, 2015

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