Transmission cooler: to by-pass the radiator or not to by-pass it

[Qyota]

Yes, but our views are backed by actual data and personal experiences. Your views are mostly BS. The only thing readers should get out of this discussion is that you like to pyss people off by not listening to reasonable explanations, and responding smugly as if that was your intent all along. Much like the banned user "mom".

The thing I'm angry about is the fact that I can't just let this thread go.

 

[tbst]

Ok, we got it. You have no evidence. You got called out and now you are feeling salts. 10-4, roger roger.

 

[quicksilvr]

Yes, but our views are backed by actual data and personal experiences. Your views are mostly BS. The only thing readers should get out of this discussion is that you like to pyss people off by not listening to reasonable explanations, and responding smugly as if that was your intent all along. Much like the banned user "mom".

The thing I'm angry about is the fact that I can't just let this thread go.

QFT! I wish I could stop coming back to this crazy discussion/argument.


I did ask a simple question....and got no response from Drcoffee. So for everyone eating their popcorn, reading this, and trying to decide for themselves which option is the best for them: I would definitely suggest you listen to the fellow who doesn't even know his own transmission fluid temperature.


What RonMaiden said has value as well. A new radiator is a great thing. Replacing old ones can help your vehicles cooling system be more efficient. I still prefer to keep my ATF permanently separate from my coolant, but that doesn't mean I won't replace my radiator when it's due.

 

[Drcoffee]

btw drcoffee, my wife thinks your an idiot and so do i.

Sometimes, the trouble is discerning who's the idiot. The idiot or the person arguing with the idiot. So I'll stop arguing with you.
--------------

tbst, science and data ecapes you. Let me let you in on a well know concept.

Anecdotal stories, a scientific fact do not make.

I will agree with you on this. if you disconnect your radiator from the transmission, you won't get a strawberry milkshake. What I won't agree with you on is that the transmission will work better, last longer with only one external off the shelf cooler. There is always the possibility that Toyota designed their transmissions strong enough to withstand hair-brained ideas like this, enabling you to beat your chest with the success of your mod. So we may never know the truth in the end.
:shrug:

 

[the great him]

Sometimes, the trouble is discerning who's the idiot. The idiot or the person arguing with the idiot. So I'll stop arguing with you.
--------------

tbst, science and data ecapes you. Let me let you in on a well know concept.

Anecdotal stories, a scientific fact do not make.

I will agree with you on this. if you disconnect your radiator from the transmission, you won't get a strawberry milkshake. What I won't agree with you on is that the transmission will work better, last longer with only one external off the shelf cooler. There is always the possibility that Toyota designed their transmissions strong enough to withstand hair-brained ideas like this, enabling you to beat your chest with the success of your mod. So we may never know the truth in the end.
:shrug:

reading all of your posts on this it just dawned on me... you really dont have any clue what you are talking about, you know just enough to be dangerous and present yourself as a fool to those "in the know". TOYOTA DID NOT DESIGN THE TRANSMISSION, it was contracted out... the A340F trans mission was built by Aisin-Warner. it is in many different vehicles, and im sure they all gave different operation temps, as not all of the vehicles are made by toyota either.

 

[Drcoffee]

these are Toyota spec transmissions.

article from TransTec.

CRASH

The Evolution of the A340

Don Cottrell, TransTec Product Technician
Aisin Warner has produced the
A340 series transmission for
over a decade. It was first introduced
in 1985 for the Toyota Pickup and 4-
Runner line. In a two-wheel drive
version, its designation is A340E. Its
four-wheel drive version used from
1985-94 is designated A340H. The
“H” suffix led some builders to think it
stood for hydraulically-shifted transmission,
but what it really represents is
that it is coupled to a hydraulic transfer
case, instead of a mechanical one. The
transmission is electronically shifted in
both the A340E and the A340H.
Pleased with the durability of the
Aisin Warner A340E transmission,
Toyota added it to the Supra line in
1986. Aisin Warner felt so successful
with the performance of their transmission
that they began to market it to
other automakers.
The first auto manufacturer in the
states that started fitting the A340
series into their own line of trucks and
sport utilities was Chrysler Corporation.
The A340 series of transmissions
produced for Chrysler was designated
AW-4. This unit was used in all 4.0
litre, two-wheel drive and four-wheel
drive Jeep Wagoneers, Cherokees,
Grand Cherokees and Comanches. The
only exception was the 1994-98 Grand
Cherokee, which used the A500.
Chrysler took a different approach
to their four-wheel drives. They went
with a mechanical transfer case instead
of a hydraulic unit like the 1985-94
Toyota four-wheel drives. This was
usually a less costly repair, because
you could separate the transfer case
from the transmission just by unbolting
it from the transmission’s adapter
housing. In Toyota four-wheel drives,
on the other hand, you had to disassemble
the transfer case to get to the
bolts that held it to the transmission. To
do the early Toyotas right, you have to
rebuild the transfer case as well as the
transmission, and add the cost of doing
this to the job.
Isuzu used the A340H in its Trooper
line since the Trooper’s inception in
1988, up through 1991 in vehicles with
a 2.6L inline 4-cylinder, and a 2.8L V6.
Isuzu, like Toyota, also had the
hydraulic transfer case that was capable
of true “shift on the fly.”
In 1990, Aisin Warner started
producing the sister to the A340E,
designated the A341E. Lexus was the
first automaker to use the A341E. It
debuted in the LS400 line in 1990, the
SC400 in 1992, the GS300 in 1993, and
the SC300 in 1998. Toyota used the
A341E in the 1993-98 Supra, paired
with the 3.0L twin cam turbo engine.
Volvo also used this unit with a
designation of AW 40 in its 960 series
from 1993-97, and its 90 series for
1998-up.
The A341E was only produced in a
two-wheel drive version. It is basically
a beefier A340E, with a shorter output
shaft and extension housing, and a bolton
flange yoke. These external characteristics
readily distinguish the A341E
from its sister, the A340E. Internally,
you will see numerous changes. There
is a different pump, clutch pack
changes, an added shift (line pressure)
control solenoid, and changes to the
valve body for line pressure modulation.
You will also notice that the lock-up
control solenoid went from an on/off
type to a pressure modulation type.
The 1993-98 Supra 3.0L turbo and
the 1998-up Lexus SC300 went one step
further on their A341E, and added a
throttle control solenoid that controls
hydraulic pressure to the back chamber
of the accumulators. This helps control
shift feel.
In 1995, Toyota decided to do away
with their hydraulic transfer case and go
with a conventional mechanical transfer
case. This was a welcome change to
most rebuilders and owners, since you
no longer had to disassemble the
transfer case and build it along with the
transmission. The new designation for
the four-wheel drive units with a
separate transfer case is “A340F.” This
unit was used in all of their four-wheel
drive vehicles from 1995-up, except for
the Landcruiser. Mitsubishi also used
the A340F in their 1995-98 Montero.
Another event that took place in
1995 was the addition of another version
of the A340 series. This new version
was designated A343F, and it was only
produced in a four-wheel drive version.
The only applications this was used in
were the high line four-wheel drives like
the Lexus LX450 and LX470, as well as
the 1995-up Landcruiser.
The 1995-97 A343F is basically an
A341E internally, with the exception of
the output shaft and some clutch pack
changes. It also uses the A340E type
valve body instead of the shift control
solenoid valve body like in the A341E.
In 1998, the A343F underwent a face lift
A
4
and had the shift control (line pressure)
solenoid added to the hydraulics, as
well as a throttle control solenoid.
All of the A340 series of transmissions
are generally very reliable. But
close attention is needed when doing a
rebuild. The valve body has had many
changes from model to model, and you
need to pay close attention to all the
check ball locations since they’ve been
moved around a lot.
One area of concern is that the
throttle position sensor on the Jeep
applications goes bad quite often,
causing what is generally described as a
neutralizing condition while at cruise.
Another weak point is the famous
“Toyota clogged shift solenoid syndrome,”
as well as problems with the
speed sensors going bad.
Several of the tech services have
good technical manuals available for
these units, and it is highly advised to
have them on hand when tackling one
of these for a rebuild.
If you think all this is confusing
enough, think again, because the latest
trend is not towards simplicity. The
new generation of 5-speed is here, and
there are two different versions out
already. The first is the A350E, and the
second is the A650E. But that’s another
story……..

 

[the great him]

both Suzuki and Isuzu use it, and J**p use the AW4, witch is almost identical, the difference is that Toyota has different plugs on it, and the external linkages are different, as are some of the mounts. the truth is Toyota went to Aisin-Warner and wanted to use this trans(as it had been out in production for several years before Toyota ever started using it) because of its reliability. this trans was not designed specifically for the 3rd gen Toyota 4runner(yes it was adapted to work specifically with it, but the design is not changed)

 

[BrianSD_42]

tbst, science and data ecapes you. Let me let you in on a well know concept.

MrCoffee,

So what exactly do you do for a living? Background in science?


:fishing:

 

[Nelsonmd]

Sometimes, the trouble is discerning who's the idiot. The idiot or the person arguing with the idiot. So I'll stop arguing with you.
--------------

tbst, science and data ecapes you. Let me let you in on a well know concept.

Anecdotal stories, a scientific fact do not make.

Ok, now you just reached mom-level ignorance... Anecdotal stories, a scientific fact do not make? All you have is anecdotal stories and blind assertions. Let me remind you...

Fact: the air cooled external coolers like what I have seen posted, such as B&M have a thermal efficiency of a 20 degrees drop "at best." If you run two you get 40 degrees in simplistic terms. If you are cool (pun intended) with that as the best you can do no matter what you happen to be doing with your truck and you also don't care if you run your tranny at below freezing temps until friction from sudge like tranny fluid can raise the operating temps up in an hours time(supposition), then I say go for.

Where is your data to support this "fact"? Numbers pulled out of your a$$ aren't considered data.

Fact: Aftermarket manufactures state that you should not install their coolers with both ports facing up. The rationale is that freezing conditions will cause the trans fluid it gel or freeze and restrict flow upon start up. The radiator helps raise the tranny fluid up to operating temp in short order. Every mechanical device has an optimal operating temperature range it was designed to function properly. When you broaden that temp range intentionally, you are forcing the machine to work outside its optimal (engineered) range causing premature wear.

Where is your data to support this "fact"? I gave you some data in opposition to your "fact", you havn't given any in support of it though.

Fact: if you re-route the trans lines away from the radiator on a new vehicle, you will void your warranty. Admittedly, anything voids your warranty but the fact remains. Good intentions aside.

Show me where in the warranty it says that. Since TRD offered a tranny cooler, I think it's reasonable to believe that adding a tranny cooler doesn't void your warranty. But even if it does, who gives a crap, no one has a warranty left on their 3rd gen anyway.

these are Toyota spec transmissions.

article from TransTec.

CRASH

The Evolution of the A340

Don Cottrell, TransTec Product Technician
Aisin Warner has produced the
A340 series transmission for
over a decade. It was first introduced
in 1985 for the Toyota Pickup and 4-
Runner line. In a two-wheel drive
version, its designation is A340E. Its
four-wheel drive version used from
1985-94 is ...

I thought evolution of design didn't matter?

What are you smoking?

 

[mexdealer]

Wow...

 

[tbst]

tbst, science and data ecapes you. Let me let you in on a well know concept.

Anecdotal stories, a scientific fact do not make.

I am still waiting on your numerical data.

Personal attacks don't bother me. It doesn't distract anyone from the fact that you have zero idea of what is going on.

Maybe it's because there is a war going on for your mind! :banana:

 

[Millerad1651]

:snacker:I'm just hoping I don't run out of popcorn before this all ends!

 

[Dous]

 

[brian4t]

You guys are jumping all over this guy. From reading what I did (not all) it seems his opinion was to just replace the radiator for the average daily driver and not adding a transmission cooler to the radiator that already has 100-200K on it. Seems logical. Now all the other facts he's posted I haven't bothered to read, it see this as an opinion thread and that's it. Given the two options I'd most certainly replace the entire aged radiator and be done with it. Given the facts that radiators can be damaged with flying debris, and not changing your coolant in regular basis it seems logical your radiator should be replaced as routine maintenance with ANY vehicle. I personally would not trust the average radiator for much over 150K, but hell you know what they say about opinions...

 

[Qyota]

Brian, it's worth reading all of it. If Mr. PhD was just giving an opinion, that'd be one thing. However, he outright challenged and refuted the efficacy of an external cooler. That's the problem most of us have with this thread. Not to mention that MOST of use with external coolers ALSO have newer radiators. I know I replaced mine when I added the cooler. No one here is refuting the benefits of a new radiator.

 

[Pikeman]

Havn't posted in a while but had to on this one.

OK a couple things first.... Koyo was the OEM radiator for Toyota for many years so arguement buy a radiator not made by Toyota is moot when you suggest buy a Koyo. I bought a Koyo because they were the OEM for Toyota.

Now to point that external coolers will not let your transmission warm up properly. Most coolers are mounted to the front of the radiator and will be warmed from the radiant heat from coolant. Also the better external coolers (B&M, Tru-cool) are a low pressure drop design with low temp bypass. meaning that when the fluid is cool and thicker it will bypass the cooling ports and flow through the bypass until it heats up and thins enough to go through. If you buy an aftermarket cooler without the thermal bypass built in then you can also add an external thermal bypass(alot like a thermostat does for your radiator). Transmission coolers are rated by GVW and also BTU(British Thermal Units) just like the burners on a oven etc. so various sizes will cool a different amount then the arbitrary 20 degree stated.

Also to add external, bypass or not bypass is a personal decision. Some deciding factors need to be considered in this decision.

1. How do I use my truck?
2. Is my truck modified or will it be in the future?
3. Will I be towing and how often and how heavy?
4. Climate I live in or most use my vehicle?
5. What condition maintenace wise is my vehicle?

Those are just some of the basic questions you need to ask when considering an external cooler. The answer to those questions can also determine the size external cooler you want/need to use. If you live in a warm or hot climate and use your vehicle hard and are modified than I highly recommend you add an external cooler. The choice to bypass or not will also add in the size consideration of the cooler. Here is a good webpage to read to get information on cooler selection.

Automatic transmission cooler guide and installation

quick excerpt at top of page.... notice it says to use in series and then gives guidelines on increasing size 1-2 times if bypassing factory system.

Transmission Cooler Quick Guide & installation
The most often asked question is should I bypass the radiator cooler when I install a auxillary cooler.
Most cooler manufactures and automobile manufactures information we have read, recommends installing the coolers In-Series with the factory radiator cooler for maxium cooling efficiency.
So unless the manufactures who have spent 1000's of hours testing different installations are wrong, the suggested cooler installation is in-series......
Transmission > Radiator cooler > Auxillary cooler > then Back to the transmission.
If you must bypass the radiator because the cooler tube is leaking or for other reasons, be sure to increase the size cooler you install by 1 to 2 sizes.

Next thing is location of your temp sending unit can give you a widely varied reading. I will try to find an article I read which talks about a person that tried all the various locations on the same vehicle and saw drastically different readings. The decision in the end is that a temp sending unit in the pan gives the most consistent and accurate reading in most cases.

I hope this has helped put the thread back on track and answered a few questions.

My set-up Koyo radiator installed winter '10 with Tru-cool 4589 (24,500 GVW) on truck with 242k+ separately. That is why I went with a larger properly sized cooler.

 

[ALBPM]

What Pikeman said......

My setup is a new Koyo Radiator with a TRD tranny Cooler in Series. Installed last summer at ~99,000 miles

:snacker::snacker:

 

[BrianSD_42]

You guys are jumping all over this guy. From reading what I did (not all) it seems his opinion was to just replace the radiator for the average daily driver and not adding a transmission cooler to the radiator that already has 100-200K on it

I actually did just that. Not trying to take sides here but I didnt feel that my situation warranted a trans cooler.

I replaced my original rad with an oem Koyo at 190k miles and see 0 reason for ME to put a trans cooler on.

I doubt a pink milkshake will happen to my new radiator that has never been reported on a new rad.

I live in San diego and rarely leave the area. Temps here vary from 40F to 85F, possibly 105F if I drive to the desert.

My trans has 0 slippage at 212k miles. I do the drain n fill every 30k. I do not know my rad temps because I have no gauge.

I'm not against trans coolers but I just didnt feel it was necessary in my situation. I totally understand why people do it.

I think people are jumping him for all reasons stated above. Also it is probably not a good idea to invoke science without scientific facts. Googling for text that supports an argument is not science.

Funny someone mentioned Mom. That guy was a 30 yo Lit major + MBA who worked at Apple. He started threads like "let me show you how to change a tail light bulb" and while I won't go into the details I do believe his background colored his posts.

 

[Snowy21]

Get in and wheel.




But honestly just do whatever makes you sleep at night. I've replaced the radiator when the TB was changed last time and that was good enough for me. The stock setup has gotten me to over 260k with zero issues pulling various (heavy) trailers and wheeling. I don't see any reason it won't make it another 260k on the same setup

 

[Steve240]

I didn't read all of this thread but I do want to mention one thing as I work in the auto industry as a engineer.

A lot of things are designed to work and mainly to keep the cost of the vehicle down. Integrating the rad and trans cooler in one unit is mainly to reduce cost, parts instalation, tooling, quality and supply chain.

Do not believe this is superior because toyota designed it. It works and its proven and a lot of vehicles use the same design. But look at any performace offroad or racing vehicle and it will have seperate cooling systems because reduction in cost is not a primary goal.