TH350 Cooling lines 101

[AndyMenon]

Hello Gents,

Wish you all a Happy Thanks Giving!
I'm trying to spend some time in the garage with my ride when I can during the long weekend and I need some quick advice on the TH350 cooling lines.

1. On the tranny end, which one's the exit, the top or bottom?
2. On the radiator end, which is the entry point into the built-in transmission cooler, the one on the driver's side, or the passenger side?

thanks much!

 

[EX JUNK]

Hello Gents,

Wish you all a Happy Thanks Giving!
I'm trying to spend some time in the garage with my ride when I can during the long weekend and I need some quick advice on the TH350 cooling lines.

1. On the tranny end, which one's the exit, the top or bottom?
2. On the radiator end, which is the entry point into the built-in transmission cooler, the one on the driver's side, or the passenger side?

thanks much!

Here you go. http://www.clubhotrod.com/forums/showthread.php?t=12306&page=2

Jim

 

[deckofficer]

TH350, TH250
Fitting Location Thread Size Flow Direction
Upper ¼" Pipe Return/in
Lower ¼" Pipe Cooler feed/out

 

[AndyMenon]

Thanks All!

But does the inlet outlets on the radiator matter?

 

[Gerry]

Thanks All!

But does the inlet outlets on the radiator matter?

Modern cars have a one way valve in the cooler lines. Easy way to find out is use a compressed air line on them both and see if one way flows and the other doesn't. Be gentle with the pressure though so as not to blow out your cooler matrix.
Look at your water rad. Hot to the top and cold from the bottom... Heat rises .

Just a by your way. Im NOT running a cooler on my 350. Corvettes didn't so why should I.

Gerry

 

[Mike]

Just a by your way. Im NOT running a cooler on my 350. Corvettes didn't so why should I.

Eh? I'm yet to see a Corvette without a trans cooler. Some of the early to mid-60s ('63, '64, '65, around in there somewhere) models had a separate cooler. HERE is an entire page given over to trans cooling lines and cooler for Corvettes.

 

[AndyMenon]

Modern cars have a one way valve in the cooler lines. Easy way to find out is use a compressed air line on them both and see if one way flows and the other doesn't. Be gentle with the pressure though so as not to blow out your cooler matrix.
Look at your water rad. Hot to the top and cold from the bottom... Heat rises .

Just a by your way. Im NOT running a cooler on my 350. Corvettes didn't so why should I.

Gerry

Hi Gerry,
My car is a basic street rod. Nothing fancy.
My radiator is t-bucket style . The transmission cooler is at the bottom with 2 holes in the horizontal plane. One on the driver side and the other on the passenger side. I will see if the test you prescribed works regardless.

thanks,
-Andy

 

[AndyMenon]

Guys,

Here is a pic of my setup. My trans-cooler set up is integrated into the radiator at the bottom and the 2 yellow arrows point to the openings.

But the problem is there is no marking of any sorts to indicate the direction of flow.

thanks,
-Andy

 

[deckofficer]

Being I use manual trans I'm not sure on this subject, but isn't the trans cooler in the radiator a closed system that is heat sinking to the coolant and not any fins to the air? If so, it wouldn't matter which of the two rad lines is in or out unless for some reason there is some valving operated by pressure.

Bob

 

[ellis8500]

The radiator trans cooler only cools the trans fluid to the same temp as the engine coolant. On the radiator you have, with a trans fluid tank at the bottom of the radiator, flow direction makes no difference.

 

[GT63]

I think the trans connection on the radiator is a little mis understood. It's purpose is not to cool the trans fluid, but to warm it up during winter months.The trans fluid doesn't move through any fins in the radiator. If you want to cool your trans fluid, you'll need to use a seperate cooler with some type of fins.

 

[TexasT]

You hit it right on the head GT, It isnt a cooler, it actually warms the fluid. I dont even have one on my TH350. Just a small loop of line to circulate.

 

[CrAlt]

You hit it right on the head GT, It isnt a cooler, it actually warms the fluid. I dont even have one on my TH350. Just a small loop of line to circulate.

the lines through the radiator do a combination of both, depending on temps...it'll help warm it up when it's cold, but it'll also cool it down when it's hot...


In a sub 2000lbs car thats only driven in the warmer weathers it prob doesn't need it for neither reason.

 

[Wild Mango]

the lines through the radiator do a combination of both, depending on temps...it'll help warm it up when it's cold, but it'll also cool it down when it's hot...


In a sub 2000lbs car thats only driven in the warmer weathers it prob doesn't need it for neither reason.

I never have had too cold problems with TH 350 trans but brother, I've had some grief with too hot. Unless you live in Alaska, bypass the heating circuit in the radiator and put in an air cooled radiator for the fluid.

 

[Corley]

the lines through the radiator do a combination of both, depending on temps...it'll help warm it up when it's cold, but it'll also cool it down when it's hot...


In a sub 2000lbs car thats only driven in the warmer weathers it prob doesn't need it for neither reason.

Finally, a correct answer...

 

[TexasT]

Well im in Texas and always owned TH350 trans and never had one ever get to hot

 

[TexasT]

Besides the Vegas and the Monzas, the th350 trans that came in them didnt even have the holes tapped into the trans for a cooler.

 

[Gerry]

Besides the Vegas and the Monzas, the th350 trans that came in them didnt even have the holes tapped into the trans for a cooler.

I ll be waiting for the shouts of disagreement but its the converter that produces most of the heat in an auto trans. While I am aware that a 'cooler' will aid warming up (there are several cars that now have temp sensors that wont let the trans shift in to top until they are warm) its main function is to cool. Heres a ditti from JW Racing when we were talking about the converter for my Topolino... A covnerter on stall for about 10 seconds will produce enough heat to take a gallon of water from cold to boiling. Its also worth noting that Hi Stalls produce more heat that standard ones. From experience past and present I am not going to run a cooler on the T. Also if you have cooler fittings in the trans casing you must loop them together.
.
We have been told by ZF that a max running temperature should be 95 degrees C and I see no reason to belive a 350 is that much different. When we build 'normal' autos for street/strip or strip application we always advise the owners to fit trans temp gauges, and not the ones with a tube feed. Always electronic ones so there are no lines with hot fluid anywhere near the driver.

Gerry

 

[TexasT]

that is true and the higher the stall the more heat generated

 

[AndyMenon]

This is a normal street application. Nothing fancy.
I haven't had the time to yank the radiator out and check for the direction of the fluid in the transmission cooler.

I would definitely need to pass it thro' the radiator as I live in New England and the fluid will have to be at nominal temperature for the trans to work right.

I have an external cooler, but before I put that in, I was wondering if I'm over engineering this thing.

Thanks,
-Andy