Transmission cooler discussion

ASSISTANCE Stock Engine-Bay Components
1

(If anyone finds anything wrong with my though process please let me know; I can’t say that I excelled in my Thermodynamics class. Also if you wanna be a smart ass and say ‘just swap it and get a manual’ you will anger the G2IC gods, so just don’t do it. I want some real input here.)

For those not familiar with how the automatic transmission cooling works:

There is an oil output from the transmission that goes into the lower (cooler) part of the radiator and then goes back into the transmission.

I am considering getting a new radiator and replacing this transmission cooler with an air cooler.

I am led to conclude that this would result it cooler temperatures both for the transmission AND for the engine. For the following reasons:

In the stock setup, the transmission fluid heat is transferred into already-cooled (by the radiator) fluid. This fluid and then pumped into the engine to do further cooling. But it is now heated a little more due to it accepting the transmission heat.

If I were to get an aftermarket air cooler, it would not dump the heat into the radiator. So the engine would get its originally cooled radiator coolant.

Heat transfer via convection is more efficient via liquid cooling rather than gaseous cooling. However, the temperature gradient is also a factor (Steeper gradients = better convection). Consider the following:

In the Stock Setup, transmission oil is cooled via “already cooled” radiator coolant. This coolant is still pretty hot though when compared to surrounding air. This is a mild gradient. When using an air-cooled transmission cooler, the air is cooler than what would be in the radiator, so this gradient is steep.

So even though the metal-to-air heat transfer is less efficient, the gradient is steeper. Which I would think would AT LEAST make it equal to the cooling power of the radiator cooler setup. And even if it’s just equal, it would be a plus, since no additional heat is added to the engine coolant.

Therefore, I would think that replacing the radiator, and getting an air cooled transmission cooler would result in cooler operating temperatures for both the engine and the transmission.

Thoughts?

2

i concur

3

i’ve been thinking of doing it on mine. i’ve always done it on my hotrods. definitely reduces tranny wear! as you know, an auto tranny’s worse enemy is heat.

4

Well getting a transmission cooler would def help with the temps from the trans fluid and would give you a better shift since the fluid is cooler then it was before. This is true in cold weather (at normal operating temps) since the fluid is not as hot as it would be in a hot summer day. Therefor it would take longer for the fluid to break down then it would running threw the rad. Not only that but, it would make the A/T last longer and prevent it from over heating. Since the A/T fluid can reach upto 300 degrees f. I rather have it under that to prevent premature wear and prevent premature breakdown of the fluid. It’s also recommended to replace the fluid every 30k. I’m considering getting a cooler for my A/T also and i’ve been doing some research on it. I can post up some links on where i’v been reading about if you like?

5

eh. Keep up on fluid changes and you should be ok. Honda tends to over think things when they design a part. I dont see how it could hurt but I wouldnt break the bank trying to make it work.

6

Well I’m gonna be getting a fluidyne-like radiator from NB Performance – and the “performance” radiators do not take into account the automatic transmission cooler.

1991Acura I’d like to see your links, thanks. I’ve done some looking myself but they all seem to be the same. I’ve been looking at the B&M ones.

7

Hey Neil, I checked with Mish. and the trans cooler they offer is still in production. No eta. yet.

8

That’s fine man. Thanks for checking. :up:

9

i was just gonna crack open the jegs catalogue and get some stuff from there. that and an in-line screw on filter kit. about $50 for everything minus the extended rubber hose. if you go to their website, you will see a few universal trans cooler packs.

jegs.com

10

Hey Neil, I found some links. I’m digging up some more as I speak. But for right now here’s a few. I’ll post up some more links if you like.
This link tells you how the cooler works for both engine oil and trans fluid.
http://www.perma-cool.com/Catalog/Cat_page02.html

This link gives you an idea on how it’s install.
http://www.automedia.com/Transmission/Coolers/pht20011001tc/1

Here’s a list of A/T coolers.
https://www.optionsauto.com/products.asp?dept=4607

For the rest of us, here’s a link to better understand how the A/T works.
http://www.familycar.com/Transmission.htm

Anyways I wonder how they would fit in our tegs. Since we have such tight spaces where the rad and where the rad looking thing is thats for the A/C along with the high pressure line for The A/C That go’s in front. But for it to work properly. It’s recommended to mount the cooler in front of the rad. I’m going to talk to my machanic sometime tomorrow since i gotta make an appointment for inspection. And how ask him whats the best way to have the coolers mounted.

11

well, i’ve seen and used two different types of coolers in the past. i’ve used the ones that are like mini radiators and ones that replace a section of line and go in-line (kinda like a heatsink. are usually a piece of billet aluminum with fins on it). the heatsink ones are a better alternative in tight spaces. the regular ones would most likely give you the best cooling overall but will eat up alot of space.

I am assuming that there is still some space in front of the A/C radiator core (condenser?) sits. installation is easy since you will pass some straps through the veins of the condenser and radiator to create a mounting point. i’ll check tomorrow to see how much space is between the radiator and bumper.

12

Neil, IMHO, if you are going to replace your radiator, the cooling of a new radiator is perfectly sufficient for your needs. Remember, it will have fresh water passages and perfect fins for dissipation of heat. Just find one that has the lower cooler portion for your tranny fluid and you will be all set.

I purchased a universal $85 all-metal radiator somewhere online, and it has been perfect for 3 years and 75K miles. It has the provision for the tranny lines, but I don’t use them because I am manual. I have considered using them for an oil cooler setup, but don’t think its necessary until I swap or build for performance.

You premise is valid on the stand-alone tranny cooler, but its probably overkill on your setup. If you want to use a radiator that doesn’t provide for the tranny cooler, you have no choice but to cool it by other means.

13

In my experience, the stand-alone transmission coolers work well. I’ve used a no-name air-cooled unit in a towing application (not on a Honda, mind you) and it definitely reduced the tendency of the transmission to “hunt”. Without the cooler, the transmission tended to downshift under load more often.

One concern is definitely placement. The cooler I mentioned is zip-tied to the front of the rad, which obviously blocks air flow to the rad. I’ve never attempted to quantify the effect of it.

14

I am assuming that there is still some space in front of the A/C radiator core (condenser?) sits. installation is easy since you will pass some straps through the veins of the condenser and radiator to create a mounting point. i’ll check tomorrow to see how much space is between the radiator and bumper.

I assuming to on how much space is there. It looks so tight thought.

15

So I went out and looked at the gap between the bumper and the A/C rad looking thing. There’s plenty of room for but you also got the high pressure line passing threw and inch away from the A/C rad looking thing. But by the looks of it, I don’t see how it can be an issue of fitting a A/T cool there. But it’s porbly easier to put one on if you have no A/C. But I don’t see how it would really effect the cooling for the engine unless theres a problem with the cooling system.