Coolant Lines Between Trans > Rad > Cooler > Trans?

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1969GTS340

1969GTS340

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I have attached a .pdf sketch of my coolant line routing with what I believe to be the correct
connector sizes and types from what I am reading on FABO. The snag I have is the transmission cooler having barbed 1/2" style ends that need to connect to a (Radiator) hard line with 5/16" Flare. I would imagine many of you have come across this mismatch and would like to hear how you worked around it?

Transmission 1/8" NPS (x2)
Radiator 5/16" Flare (x2)
Trans Cooler 1/2" barbed (x2)


243190083_2624025181239092_1428036397886795547_n.jpg
 

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Last month I replaced the 46re in my 02 Ram. Talking with the production manager for Transmission exchange in Portland. He said it was best to not use the build in rad cooler and just use the large external trans cooler. What I have see, is both my transmission and coolant running cooler temp than before. Also, if the rad is old, even flushed, there will be build up of converter / clutch material in the trans cooler part that will never get cleaned out...
 
Scody21 said:
Last month I replaced the 46re in my 02 Ram. Talking with the production manager for Transmission exchange in Portland. He said it was best to not use the build in rad cooler and just use the large external trans cooler. What I have see, is both my transmission and coolant running cooler temp than before. Also, if the rad is old, even flushed, there will be build up of converter / clutch material in the trans cooler part that will never get cleaned out...
Click to expand...

Interesting... I have read many a debate on here regarding the use of the radiator in conjunction with a cooler. My application is strictly a drag car with a 9" convertor. Based on that combination it seems most favor running both the radiator and cooler. However, a building up of clutch shrapnel from the transmission is something I haven't heard before.
 
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1969GTS340 said:
Interesting... I have read many a debate on here regarding the use of the radiator in conjunction with a cooler.
Click to expand...
notice the different parts of the country / world the people in some of those threads inhabit. people from way up north and those from the south trying to compare notes.
1969GTS340 said:
However, a building up of clutch shrapnel from the transmission is something I haven't heard before.
Click to expand...
seems that would happen in any cooler then. when you change the fluid you could drop the lines and blow them out
 
Aside of the lines running through one or both R/C, are there any suggestions on adapting the two style/size lines in a secure neat fasion?
 
Which line on trans is oil out? front or rear? Thanks
 
Keep in mind that transmission fluid needs to be at a certain temperature to work so a trans temp gauge would help you narrow down what the car needs. You can place a filter inline with the cooler to prevent particulates from running through the lines and cooler.
 
If it was me....

I would run the flow this way...

  1. Transmission line out
  2. To external trans cooler inlet
  3. External trans cooler outlet
  4. To internal trans cooler inlet.
  5. Internal trans cooler outlet to trans inlet.

Here is my logic...

If you cool the trans fluid before it gets to the internal cooler it does not add any or much heat to the coolant. Once the coolant heats up to the propper operating temp it helps the trans maintain its propper operating temp.
 
Thanks Dano. I do have a trans temp guage to monitor. But don't have any previous history on where the temp will run since the car is a brand new build from the ground up. Just lookig to tie up these loose ends and fire the engine for break in.
 
Either way I route the lines or eliminate the radiator, it still comes.down the my original question. What is the slickest way to connect the chiller 1/2" barbed lines to the 5/16" flared transmission lines. Is there an adaptor or fitting that mates the two?
 
mopowers said:
Yes- they sell barbed 1/2" to 5/16" adapters.
Click to expand...

I'm picturing a female 5/16 flare on one end and the other end needs to go onto the barbed end of the chiller. Do you know the brand name?
 
1969GTS340 said:
Either way I route the lines or eliminate the radiator, it still comes.down the my original question. What is the slickest way to connect the chiller 1/2" barbed lines to the 5/16" flared transmission lines. Is there an adaptor or fitting that mates the two?
Click to expand...

I used JIC fittings which are steel versions of AN fittings and nylon hydraulic hose as it was cheaper than the stock steel lines from dorman. Could also use stainless steel hose.
 
Weatherhead is a common brand name. Head over to the site and see whag you can find.
Inverted flare to hose barb should be easy.
 
Scody21 said:
Last month I replaced the 46re in my 02 Ram. Talking with the production manager for Transmission exchange in Portland. He said it was best to not use the build in rad cooler and just use the large external trans cooler. What I have see, is both my transmission and coolant running cooler temp than before. Also, if the rad is old, even flushed, there will be build up of converter / clutch material in the trans cooler part that will never get cleaned out...
Click to expand...
Go figure, a guy that sells transmissions who gave you that info. I’d say he is doing a good job at getting return customers.
 
xLURKxDOGx said:
Go figure, a guy that sells transmissions who gave you that info. I’d say he is doing a good job at getting return customers.
Click to expand...

There’s a 3 year warranty on the reman. So I’d say not. Rest of the companies are 1 year. I had a temp gauge in before with stock set up and now bypassing the rad cooler. Trans runs about 15* cooler. Heat is the enemy of auto transmissions.
 
Tooljunkie said:
Weatherhead is a common brand name. Head over to the site and see whag you can find.
Inverted flare to hose barb should be easy.
Click to expand...

Thanks Tooljunkie. My local Fastenal shop had the fitting you recomended. I'm good to go. Thanks for all the input guys.
 
FWIW...I have an 8" converter that stalls at 5000 rpm. I bypassed the radiator and use a separate Derale cooler that has its own elec fan. Temp sender is on trans output line. At the track, trans leaves the line at 150-160 and is at about 180 max at the end of the run. I don't bother to turn on the fan as it cools back down on the way to the pits.
On the street, I watch it and if I get a bit "frisky" with the car, I may sometimes flip the fan on when the trans hits 190-ish. Cools it right down.
Someone mentioned that rad coolers are used from the factory along with a separate cooler. Keep in mind that early after startup, the rad cooler is a trans oil warmer. That then reduces the friction in the trans which improves fuel economy. And every automaker does all they can to improve FE. A separate large trans cooler without going through the rad could easily be made to take care of the cooling needs but that would defeat any FE benefits during warmup.
 
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