Thoughts on Transmission Coolers>?

[ULVER]

My Ford Police Interceptor, came with a tranny cooler manufactured by Long Brand, and rated at 7,500lbs. GVW.

Georgia summers are brutal, so I upgraded to a Hayden rated at 30,000lbs. GVW---basically it was intended for a mobile home.

You would think, they would be standard equipment on every car, leaving every factory. Why not? Talk to any transmission shop, and they'll tell you they should be, but they hope they never are.

 

[T-Keith]

Almost all cars come with an in-radiator cooler. Axillary coolers are available on some models, usually trucks and police vehicles. Some argue that an axillary coolers are not needed or even harmful, but I think that's just from experience with improperly installed coolers.

-T

 

[olympic]

Yep, the cooler built into the radiator is just barely adequate for light driving. Any amount of stop and go or "spirited" driving will cook the ATF real quick. A large stacked plate cooler is the way to go. Mount it either directly to the radiator or behind a large opening in the grill. And always install the auxillary cooler in series(after) the radiator cooler.

The only caveat here is if you live in an area tha has really cold winters. In this situation you must either install a winter front on the car or cover up the majority of the cooler to prevent over-cooling the ATF.

 

[darkdan]

If they gave everyone tranny coolers....who'd buy new transmissions?

Hmmmm, so car manufactors should spend an extra $100 to not make another $1500 down the road?

=)

 

[unDummy]

If automakers built a car that had the features that everyone wanted, noone would be able to afford it.

The cost accountants hold the leashes. Engineers and marketeers wear collars.

A fluid thermostat can be used for those who live up north. Get the biggest cooler that fits!

 

[Sparkman]

Are tranny coolers available that are thermostatically controlled similar to oil coolers, just at a lower temperature?

 

[JustinH]

yes. Check out bulkpart.com, they have some coolers that are for cold climates such as wny. The one I have is in bypass mode until the fluid warms up.

 

[TheTanSedan]

. . and DO NOT attach the auxiliary heat exchanger to the AC condenser or to the radiator; they weren't meant to support a load. Ordinary vibration, whatnot, can cause the core of either to begin to weaken.

Take the time to attach with metal strap; vibration isolate with some plumbing bushings under fasteners.

Be certain hose is out of the way of all other components, etc, and the hoses are themselves not exerting a strain on coolers. Hose bends ought not to be less than 3.5" diameter.

Good luck.

 

[1maniac]

The company I work for did a trial with oversized external ATF coolers on their fleet vehicles. These vehicles run at least 10 hours a day and fall into the category of "super severe service." The transmission were failing at about 25k-30k miles. Most of the vehicles with the external oversized ATF coolers never had to have the transmissions replaced again.
Made a believer out of me.

 

[Sparkman]

quote:

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Originally posted by JustinH:
yes. Check out bulkpart.com, they have some coolers that are for cold climates such as wny. The one I have is in bypass mode until the fluid warms up.

---

Thanks!! They have really good prices on magnefine filters too.

 

[DJ]

You know guys I swapped to a high stall converter and a special fluid blend my tranny builder recommended and even with just the in rad. I had a hard time getting the tranny temp up to 190. A lot of the heat is actually just caused by cheap OEM torque converters as far as I can see honest my 2800stall 9.5" converter ran as cool as the stock 1400stall 12"(car is a 96 Caprice putting out something over 320hp). So I would argue that in many cases the stock coolers are good just the TC is built poorly and creating too much heat, but more cooling is cheaper than a good TC so I guess most of you will still go that route.
There are few tranny cooler manufacturers so don't get caught up on brand but more features. I bought a Tru-cool it is a plate style and is the same as the B&Ms that use a viscosity based bypass circuit, not a true thermostat but better than nothing. I also run a Permacool remote filter setup. I run the cooler and filter not because I have to but because I have a lot of $$$$$ sunk into my tranny and TC total they cost me maybe $90 with the shipping seemed like good insurance to me, oh and the cooler I got is actually fairly small.
Another thing to note is if you have an OEM external take a second look at that I know that the Caprices that got them really had them mouted poorly severl inches away from the condensor and really almost tucked behind the bumper I am sure other cars are like this too. While I agree that mounting to the condensor/rad. is a bad idea you do want the cooler close so that in stop and go the fans pull air through the cooler not just around. Also consider mounting it low since most through rad. airflow these days comes from below the bumper. If the car has dual electric fans figure out which one is the primary and mount in front of that one, might seem obvious but could be easily overlooked.

 

[crossbow]

Stock Mazda 6s ATX (5sp not the new 6sp) runs the ATF fluid at around 193-195F at idle. (Sigh). One can only imagine how hot the fluid gets under stressful situations.

With a 16,000 GVW B&M mounted 2 inches in front of the condensor (direct airflow through it), and inline with the radiator cooler, temps @ idle dropped to a much more respectable 160F. Shifting improved, as did overall transmission performance.

Later in the 04 Mazda 6s ATX wagon, mazda decided to "quietly" add an additional auxilary cooler...confirming what the ethusiasts knew all along...the tranny was getting far too hot.

 

[JohnBrowning]

Transmission coolers are a good thing if they are needed. Air only transmission coolers are the way to go! With the air only style their is no worry of coolant contaimination ever! Their are obviuos issues though with coolers and that is that they always creat additional leak paths! The more complicated any circuit is the more that can go wrong. It is always better to design a system with enough total lubricant volume so that the fluid does not have heat saturation concerns. It is also beter to use a better lubricant. Any type of cooler related plumbing will always fail when you can least afford for it to fail.

You always have to weigh all the pro's and con's before any good comprimise can be had. It has been my expercince that in all but the most demanding server service that most vechiles do fine with a switch to synthetic fluids with the highest ester content you can find!

Manufactures are really bad today about not giveing componets adequate airflow. I also think alot of manufactures make their sumps for transmissions too small.

 

[Steve S]

J.B. I would say most new cars suck.

 

[T-Keith]

quote:

---

Originally posted by olympic:
. And always install the auxillary cooler in series(after) the radiator cooler.

---

I'm going to have to disagree with you there. Although it would be ideal to lower the ATF temperature below the engine coolant temp slightly, adding the axillary cooler after the radiator cooler gives you the risk of over cooling. Adding it before ensures that your fluid runs at the same temperature as your coolant, which is very close to the ideal temperature. This is how most factory axillary coolers are installed.

-T

 

[1maniac]

I was at the part sstore and pulled out a few ATF/oil coolers and they all reccommend placing the cooler after the radiator cooler, not before it.

 

[JustinH]

thats right. After the heat exchanger.

The purpose of this is to allow the fluid to warm up on cool days.

If you live in florida or something, then you can just eliminate the radiator cooler all together, and just use a transmission cooler.

I do this one my racecar, that I only drive in summer.

Its best to run hardlines all the way from the transmission to your cooler, those rubber lines are apt to rupture.

If you must use rubber lines, make sure they don't rub on anything. Use zip ties to hold them in place, and consider buying some hose loom to protect the rubber from rocks or debris.

Nothing sucks worse than a trans losing fluid, and you don't notice it until its too late.

 

[thegoose]

It's kind of freaky that this topic should come up now. I was thinking about attaching a transmission cooler to our taurus over the long weekend. The tranny in the taurus' are not their stongest feature at all. I called a couple of reputable transmission service centres around town and both said the same thing. Unless you are towing or what they consider "severe conditions"-namely taxis and police cars, they are not necessary.
I suppose it all comes down to peace of mind, in the same way that we all have our own opinions about the type of oils and filters we install in our own vehicles.

 

[crossbow]

Ask yourself this...why would a transmission shop...which makes money off fixing broken and damaged transmissions...want your transmission to last forever?

 

[Tommy]

Racing, towing, sure......but do all cars really require an extra tranny cooler? How much power is being transmitted through the torque/transmission when cruising down the highway? How often (and for how long) does your transmission see the maximum horsepower of the engine? I would bet that for most passenger vehicles, there would be more to gain from extra filtration than from coolers. Lets face it, filters in the sump (suction side filters) have to be coarse by nature, some vehicles use only a screen here. Most vehicles really have NO transmission filtration in my books!