Is this cooler too large?

[74 Laguna]

I am wanting to install an external transmission cooler on our '97 Town Car. We do not pull a trailer. The cooler is a LPD design and it is 8 1/2" X 22 3/4" X 1 1/4" and is rated at 40,000 GVWR.

Does anyone think this cooler is too large for this vehicle?

I know people do not agree on if should to use the cooler in the radiator along with the external cooler but I am going to run it by itself. Years ago I had a transmission ruined by the cooler in the radiator breaking and mixing fluids.

 

[chas3]

what's the weight on your town car? i added a 16,000gvwr cooler in series with the stock radiator cooler and that seems to have been plenty for a '99 firebird (about 3500 lbs).

 

[T-Keith]

Keep the cooler in the radiator, they are much better then the older ones and they have an added benefit. If you plumb the auxiliary cooler before the factory one it will ensure that the tranny fluid never cools down too much and stays near the optimal temperature.

-T

 

[mechtech]

Standard procedure is to route the trans fluid through the stock radiator cooler, and then through the aftermarket cooler, to the trans.
No such thing as a too big trans oil cooler.
Always err on the large side.

 

[Bret Chase]

quote:

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Originally posted by T-Keith:
Keep the cooler in the radiator, they are much better then the older ones and they have an added benefit. If you plumb the auxiliary cooler before the factory one it will ensure that the tranny fluid never cools down too much and stays near the optimal temperature.

-T

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if you hook it up that way, you might as well not not bother with the aux cooler, as you're just going to heat your just cooled fluid back up by running it through the radiator's 195deg coolant. I disconnected my truck's in tank cooler last year and was rewarded by an average 50 deg drop in ATF temp and no coolant temp creep while towing on grade. it also made no visible difference in the winter temp caracteristics... the trans was running just as cold as it was before. and yes, I do have a temp gauge.

 

[Gary Allan]

quote:

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f you hook it up that way, you might as well not not bother with the aux cooler, as you're just going to heat your just cooled fluid back up by running it through the radiator's 195deg coolant.

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I don't agree. Your lower rad temp is just fine for your trans. What you don't want is for the ATF to be too hot to exchange enough btu's to get to that temp. I would actually run it through the aux first and then use the in tank cooler to buffer it to a stable temp ...then everything is sort run by your coolant thermostat. Never cool too long ...never too hot.

 

[XS650]

quote:

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Originally posted by Gary Allan:
I don't agree. Your lower rad temp is just fine for your trans. What you don't want is for the ATF to be too hot to exchange enough btu's to get to that temp. I would actually run it through the aux first and then use the in tank cooler to buffer it to a stable temp ...then everything is sort run by your coolant thermostat. Never cool too long ...never too hot.

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That may be better, but it's not obvious that it will always be. The lower coolant tank temperature will be coolest when you would want to heat the tran fluid (cold weather) and will be hotter than you want the trans fluid to be when your cooling system is working at it's upper limits.

 

[Gary Allan]

Well, sure, you'll have a variance between hot and cold weather. My feeling is that you'll dump a big amount of the thermal load through the auxillary cooler. If it's cold, you'll pick up a little in the tank ...in hot weather you'll pick up a little more. Now this totally assumes that your rad is up to the demand year round. I would think if you don't over heat, your lower rad temp would be an acceptable temp for your trans. He's going pretty big here. Sizing would surely have impact. In hot weather, he may very well be helping the rad by introducing cooler fluid into the tank.

My only thought is that it's sensible in a 4 season climate to incorporate the tank for, at least, some warming ability. With a big, stand alone, cooler you are probably delaying lockup and other functions in the transmission to the point of impact on fuel economy and whatnot in colder weather. I guess it would work just as good the other way around from the trans end of things. I just think that configured this way you shave the extremes in a sympathetic manner ..shunting the fringe to the system that can tolerate it the most.

 

[Bret Chase]

quote:

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Originally posted by Gary Allan:
He's going pretty big here.

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for a towncar, I'd call it flipping huge. In any HD truck that I've looked at w/ a factory aux cooler, it's always plumbed after the oil to water cooler. I'm happy with my setup, it works quite well.

 

[T-Keith]

The ideal temperature for ATF is around 200 deg. Cooling it to abient air temp is not nessecailly a good thing. For the same reason you can cool an engine too much, you can cool a tranny too much.

Plumbing the auxillary cooler is not pointless, it's the only way that makes sense. Most FACTORY coolers are run that way.

-T

 

[MN Driver]

Wouldn't it be a good idea to have some form of an ATF thermostat that would open the flow to the external cooler once the transmission reached a specific temperature allowing the ATF cooler to do it's job from there? That way you would get the ATF up to temp quickly and then once up to temp, it would keep it plenty cool. They make these for oil coolers, why not something like this for an ATF cooler? That is what make me wonder whether or not I want an ATF cooler because in MN I used to drive home from work after midnight in the winter and sometimes the -30 or -40 degrees F below zero, it wouldn't lock up AT ALL during a 10 minute drive home. That is what makes me want to not have a cooler. If I had one I would definetly have it after the radiator based cooler so that the fluid could be as cool as possible, or have it standalone(With an ATF temp gauge either way). If I needed to have one, I would probably disconnect the thing in the winter, I'd hate to not be burning off any consensation building up in the transmission over an entire season.

 

[74 Laguna]

What about the new stacked plate coolers that only uses the top two rows of the cooler untill the fluid reaches a certain temp. Wouldn't that let the transmission heat up fairly fast?

Also if you do not run the hot transmission fluid into the radiator wouldn't that help keep the engine temps. down?


I really do not know, that is why I am asking others that might.

 

[XS650]

quote:

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Originally posted by T-Keith:
That's why plumbing it before the radiator would be perfect for you. You basically have a thermostat controlled temp around 200 deg. What else do you want?

-T

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The bottom (cold) tank of the radiator isn't thermostically controlled. It's temperature varies quite a bit depending on cooling load, airflow and ambient temperature.

 

[Gary Allan]

Yes, if you think about it ..it would be a little hard to maintain your engine temp @ 205-210 with 200 degree inlet temps to the engine. In the winter, in my 4 banger ..if it's cold enough when I'm at idle with the heat and blower on full ..the engine temp will take a slight dive. Apparently I have a large enough heater core to allow excess cooling with the thermostat closed. Eventually my rad would get pretty cool I would imagine.

All the factory setups that I've seen are plumbed to the tank first and then to the auxillary cooler. This is designed for maximum heat rejection. These, however, are spec'd for size. In the case of an overly large cooler, I don't necessarily think that you want to cool the fluid as much as you can ..hence my bassackwards thought for the sequence.

 

[punisher]

Ford released a factory add-on cooler for this vehicle as part of the TSBs(98-8-7)for the long running converter shudder concerns. Likely to be expensive as ****, although FoMoCo does sometimes surprise us and drop parts costs on recall/program covered components to rock bottom prices to save on the bottom line since recalls and most TSBs are paid for by corporate anyway.

The mount kit places the cooler under the hood latch away from the radiator. Some kits come with all new transmission lines with the appropriate ends so you dont have to cut and splice.
F5AZ-3D746-AA COOLER
F8VZ-7K177-AA MOUNT KIT

I did a lot of these kits, all were easy to install, some easier than others. TC/GM/CV all had replacement cooler lines in the kit.

Proper fluid flow, TRANS>RADIATOR COOLER>AUX COOLER>TRANS.

 

[T-Keith]

quote:

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Originally posted by XS650:

quote:

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Originally posted by T-Keith:
That's why plumbing it before the radiator would be perfect for you. You basically have a thermostat controlled temp around 200 deg. What else do you want?

-T

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The bottom (cold) tank of the radiator isn't thermostically controlled. It's temperature varies quite a bit depending on cooling load, airflow and ambient temperature.

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Last time I checked most modern cars have a horizontal radiator. Keep in mind that sometimes the cooler lines are on the input side and other times they are on the output side. Either way they are still much closer to a safe temperature in the winter then the air.

-T

 

[XS650]

quote:

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Originally posted by T-Keith:

quote:

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Originally posted by XS650:

quote:

---

Originally posted by T-Keith:
That's why plumbing it before the radiator would be perfect for you. You basically have a thermostat controlled temp around 200 deg. What else do you want?

-T

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The bottom (cold) tank of the radiator isn't thermostically controlled. It's temperature varies quite a bit depending on cooling load, airflow and ambient temperature.

---

Last time I checked most modern cars have a horizontal radiator. Keep in mind that sometimes the cooler lines are on the input side and other times they are on the output side. Either way they are still much closer to a safe temperature in the winter then the air.

-T

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I added "(cold)" for those who needed a little extra help.

 

[T-Keith]

That's why plumbing it before the radiator would be perfect for you. You basically have a thermostat controlled temp around 200 deg. What else do you want?

-T

 

[74 Laguna]

Punisher,

I did find these parts listed on the internet.
F5AZ-3D746-AA $179.60
F8VZ-7K177-AA $138.82

Does this sound about right?

Not as bad as what I thought they might be.

I could not find out how big the cooler is, do you remember?

Since you have seen them and installed them do you think I would be better off with the factory unit or a good Tru Cool unit?

Thanks


Originally posted by punisher:
Ford released a factory add-on cooler for this vehicle as part of the TSBs(98-8-7)for the long running converter shudder concerns. Likely to be expensive as ****, although FoMoCo does sometimes surprise us and drop parts costs on recall/program covered components to rock bottom prices to save on the bottom line since recalls and most TSBs are paid for by corporate anyway.

The mount kit places the cooler under the hood latch away from the radiator. Some kits come with all new transmission lines with the appropriate ends so you dont have to cut and splice.
F5AZ-3D746-AA COOLER
F8VZ-7K177-AA MOUNT KIT

I did a lot of these kits, all were easy to install, some easier than others. TC/GM/CV all had replacement cooler lines in the kit.

Proper fluid flow, TRANS>RADIATOR COOLER>AUX COOLER>TRANS.

 

[punisher]

It is a small cooler, no more than 10" wide and 6" tall, however it was the high efficiency flat plate type, not a tube style cooler. It was just used to lower trans fluid temp 15-20 degrees to slow down fluid breakdown between services.

Personally, those prices you quoted seem a bit high for what you get.

EDIT: I looked at those Tru Cools/Derale/Hayden plate type coolers and the one we used looked exacly like those, even the mount brackets are familiar.. The more I look, the cooler from Ford was a 4"X11" unit.