Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Transmission ???'s

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Jimmy Buffett, Nov 7, 2000.

  1. Jimmy Buffett

    Jimmy Buffett Registered Member

    Joined:
    May 3, 2000
    Posts:
    19
    Likes Received:
    0
    Location:
    Eastern North Carolina
    Transmission ???\'s

    I have a TH350 in my Jimmy. There are two cooler lines running to the radaitor. Which one is the intake and which one is the out flow. When I bought my truck a tranny cooler had been installed and I think it is in wrong. Follow me here. Shouldn't the fluid coming from the transmission go to the radiator (top) and then out (bottom) to the tranny cooler than back to the tranny. To me this makes sense, keeping the transmission fluid cooler than running it though the tranny cooler and then through the radaitor cooler. Basically I just need to know which line is which so I can make sure they are plumbed right. Any help would be appreciated.
     
  2. 90K5

    90K5 1/2 ton status

    Joined:
    Jun 1, 2000
    Posts:
    3,719
    Likes Received:
    0
    Location:
    Lubbock, TX
    Re: Transmission ???\'s

    The top is the input and the bottom is the return line. I doubt it really matters which way the cooler is plumbed though, after all a cooler is better than no cooler no matter how it is plumbed.

    90K5
     
  3. Jimmy Buffett

    Jimmy Buffett Registered Member

    Joined:
    May 3, 2000
    Posts:
    19
    Likes Received:
    0
    Location:
    Eastern North Carolina
    Re: Transmission ???\'s

    90K5 thanks for the help .... but ....
    Which one is the input and which one is the return on the transmission? I think that they have the return at the top of the radiator and the the input at the bottom. Is there any other way to tell which is which?
    Don
     
  4. 90K5

    90K5 1/2 ton status

    Joined:
    Jun 1, 2000
    Posts:
    3,719
    Likes Received:
    0
    Location:
    Lubbock, TX
    Re: Transmission ???\'s

    If you still aren't sure, you could pull off one of the lines while its running and see which way the fluid goes. Kinda messy though...

    90K5
     
  5. Jimmy Buffett

    Jimmy Buffett Registered Member

    Joined:
    May 3, 2000
    Posts:
    19
    Likes Received:
    0
    Location:
    Eastern North Carolina
    Re: Transmission ???\'s

    Yeah ... I thought about that ... I might just take it to AAMCO and have them tell me!
    Don
     
  6. Wheels

    Wheels 1/2 ton status

    Joined:
    Aug 18, 2000
    Posts:
    638
    Likes Received:
    0
    Location:
    Native Floridian living in Oklahoma, USA
    Re: Transmission ???\'s

    Had to read this just because I'm a Parrothead myself. Top to top, bottom to bottom. Top is pressure, bottom is return. It is better to run the top line into the radiator, then out to the cooler, then back to the tranny. This steps down the cooling effect. If you aren't running an external cooler, it don't matter which way the lines hook up.
     
  7. Jimmy Buffett

    Jimmy Buffett Registered Member

    Joined:
    May 3, 2000
    Posts:
    19
    Likes Received:
    0
    Location:
    Eastern North Carolina
    Re: Transmission ???\'s

    Wheels - Parrot Heads rule! I just went out and looked on my Jimmy ... as I figured, it is routed to the tranny cooler first than the radiator. I'm putting on an external Tranny fluid filter and noticed that the lines might have been plumbed wrong. I really appreciate you help ... and as Jimmy says "... if we all couldn't laugh ... we'd all go insane..."
     
  8. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,073
    Likes Received:
    486
    Location:
    Grand Rapids area
    Re: Transmission ???\'s

    It is better to have the aftermarket cooler after the radiator cooler, because this allows you to return fluid to the tranny that is cooler than your engine coolant. If you go to the cooler first and then the radiator, the radiator may actually transfer heat from the engine coolant into your transmission fluid.

    The better you cool your transmission fluid, the worse you make the situation for your engine cooling system, but generally it is not enough to cause a problem.

    New 4x4 driver: "A lot of money in that truck, eh?"
    Me: "Oh, about 1/4 of a new one"
     
  9. Jimmy Buffett

    Jimmy Buffett Registered Member

    Joined:
    May 3, 2000
    Posts:
    19
    Likes Received:
    0
    Location:
    Eastern North Carolina
    Re: Transmission ???\'s

    Yeah ... that is what I figured. When I started to put on the remote tranny fluid filter I thought that the cooling lines were plumbed wrong. I thought I would post here to see if I could get a confirmation and I have. I appreciate the help.

    "... if we all couldn't laugh ... we'd all go insane ..."
     
  10. Wheels

    Wheels 1/2 ton status

    Joined:
    Aug 18, 2000
    Posts:
    638
    Likes Received:
    0
    Location:
    Native Floridian living in Oklahoma, USA
    Re: Transmission ???\'s

    Love it, that's been my motto in life since he came out with Changes in Latitudes.
     
  11. 88blazer

    88blazer Registered Member

    Joined:
    Sep 26, 2000
    Posts:
    18
    Likes Received:
    0
    Location:
    Western PA
    Re: Transmission ???\'s

    Where you put the external cooler depends on your latitude. Sorry, couldn't help myself.

    If you live in a warmer climate, then running the cooler after the rad would be more effecive.
    But if you live up north, running the cooler before the rad will help the trans fluid warm up on those cold winter mornings.





    http://bernie.4t.com
     
  12. Jeff427

    Jeff427 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,186
    Likes Received:
    0
    Location:
    Gladwin, MI
    Re: Transmission ???\'s

    I just checked in the book Turbo Hydra-matic 350 Handbook, and Ron Sessions states "The fluid return line always enters the right side of the [transmission] case at the top; it exits crossflow radiators at the top."

    Jeff427
    <font color=red>Mud Dog Off Road Club</font color=red>
    http://muddogoffroad.coloradok5.com
     
  13. Jimmy Buffett

    Jimmy Buffett Registered Member

    Joined:
    May 3, 2000
    Posts:
    19
    Likes Received:
    0
    Location:
    Eastern North Carolina
    Re: Transmission ???\'s

    So ... the return is on the top of the tranny and the radiator? So ... the pressure line is the bottom on the tranny and the bottom on the radaitor? So ... I should run the bottom tranny line to the bottom of the radiator; top of the radiator to the tranny cooler; tranny cooler to the external tranny fluid filter; external tranny fluid filter to the top return line on the tranny? Is this correct?


    "... if we all couldn't laugh ... we'd all go insane ..."
     
  14. 88blazer

    88blazer Registered Member

    Joined:
    Sep 26, 2000
    Posts:
    18
    Likes Received:
    0
    Location:
    Western PA
  15. dumbfounded

    dumbfounded 1/2 ton status

    Joined:
    May 20, 2000
    Posts:
    176
    Likes Received:
    0
    Location:
    Castalia, NC
    Re: Transmission ???\'s

    This has been discussed a bunch of times and although it may not sound correct but It needs to go through the external cooler first then to the radiator so it isn't over cooled. Unless you have an external cooler with a thermostat (99% of them don't). A too cool tranny is just as bad an an overheated one. Take my advice. Optimum tranny temp is 180degrees about the engine coolant. Try looking back in the search I've explained this alot better before.

    Love, Peace, and Hair Grease...........
     
  16. Jeff427

    Jeff427 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,186
    Likes Received:
    0
    Location:
    Gladwin, MI
    Re: Transmission ???\'s

    "In-Series Installation-You can plumb a transmission cooler in one of two ways: in-series or free-standing. The in-series, or tandem, hookup uses the existing radiator fluid to water cooler-if so equipped-in series with an auxiliary cooler. It's impossible to overcool the transmission with this setup, making it an excellent choice for vehicles operating in cold weather. This installation is also the only type permitted under many new-car warranties.
    Splice the auxiliary cooler into the return line. If your not sure which one it is, follow the cooler lines to the transmission. The fluid-return line always enters the right side of the case at the top; it exits crossflow radiators at the top."-TURBO HYDRA-MATIC 350 HANDBOOK by Ron Sessions Page 222
    In the quote above you can see Ron Sessions clearly states that it is impossible to overcool the transmission with the auxiliary cooler plumbed into the return line, after the factory tranny cooler.
    Jimmy Buffett,<blockquote><font size=1>In reply to:</font><hr>

    So ... the return is on the top of the tranny and the radiator? So ... the pressure line is the bottom on the tranny and the bottom on the radaitor? So ... I should run the bottom tranny line to the bottom of the radiator; top of the radiator to the tranny cooler; tranny cooler to the external tranny fluid filter; external tranny fluid filter to the top return line on the tranny? Is this correct?

    <hr></blockquote>

    Yes you are correct Jimmy.

    To anyone who is running a TH350, I highly recommend you pick up a copy of the TURBO HYDRA-MATIC 350 HANDBOOK by Ron Sessions, even if you don't plan on rebuilding your transmission. The information Ron provides on troubleshooting and maintaining is invaluable, not to mention the detail in which he covers removal and installation, as well as rebuilding and modifying.

    Jeff427
    <font color=red>Mud Dog Off Road Club</font color=red>
    http://muddogoffroad.coloradok5.com
     
  17. Jimmy Buffett

    Jimmy Buffett Registered Member

    Joined:
    May 3, 2000
    Posts:
    19
    Likes Received:
    0
    Location:
    Eastern North Carolina
    Re: Transmission ???\'s

    I Just got an Auto Meter Transmission Temperature Gauge. I guess I'm going to hook up the lines with the auxillary cooler first and the radiator second and then vice versa. I'll let you all know how it turns out! Thanks for everyone's help on this! And I'm getting that TH350 book from Amazon as soon as I'm done posting this!

    "... if we all couldn't laugh ... we'd all go insane ..."
     

Share This Page