tranny cooler

[svxfiles]

Originally Posted by benebob

That's the thing I don't think anybody has really gotten a true baseline by installing prior to the cooler.

After reading your post, Ben, I decided to run the Subaru Select Moniter and post here.
On my stock Pearlie, 125k, with pure synthetic trans oil (BG products) and 4.44s and only the factory trans (rad) cooler.
Outside air temp; 62-61f
Engine temp; 198f
Trans temp after 6.5 gentle miles 128f, at 8 miles 145f

On Di's stock 92 SVX, 155k, with generic Dexron3, and the stock (rad) cooler;
Outside air temp; 58-60f
Engine temp; 203-207
Trans temp; 154 after 6 miles, and just stayed at 154 for the next 22 miles.

Note, the Pearlie was started cold, and Di's was started warm.
More later. Tom
Note, both the synthetic trans oil, and the 4.44s should help to keep the oil temp down.

[dannmarr]

Before I purchase a cooler, I have one more question. A mechanic, who also races cars for a living told me; a cooler isn't neccessary as long as you use a full synthetic oil. How true is this?

[mbtoloczko]

Originally Posted by dannmarr

Before I purchase a cooler, I have one more question. A mechanic, who also races cars for a living told me; a cooler isn't neccessary as long as you use a full synthetic oil. How true is this?

Not true. Synthetics do little to control temperature. They may be slightly slicker which might lower the temperature a degree or two, but its inconsequential. He probably means that synthetics can handle higher temperatures, which is true, but many other parts in the tranny don't do well with higher temperatures, such as seals, and clutches.

[Alycone]

Whoru465
I know because there were no shift problems and my fluid was clear and pink, not burned. Don't need a gauge to figure that out. The fluid continues to remain in good shape. Any other questions I can answer?

I guess its kinda like heart disease - your first symptom is often death. Or at least, by the time you get symptoms, the damage is severe and irreversible.

Boston? Cool - I've got family in Salem.

[dcarrb]

View adding a supplemental ATF cooler as cheap preventive maintenance. It's certainly not going to do your transmission any harm to run a bit cooler.

dcb

[Whoru465]

Originally Posted by dcarrb

View adding a supplemental ATF cooler as cheap preventive maintenance. It's certainly not going to do your transmission any harm to run a bit cooler.

dcb

Yea, what he said

And yes, Boston is cool.... And witches live in Salem, we don't go there

Edit: I almost forgot, I have relatives in Washington...

[immortal_suby]

Originally Posted by benebob

That's the thing I don't think anybody has really gotten a true baseline by installing prior to the cooler.

I did that on my wife's svx a few years ago - I'm sure I posted it here and a search would probably uncover it. I'll look later on.

[Alycone]

Originally posted by Whoru465
And yes, Boston is cool.... And witches live in Salem, we don't go there

Edit: I almost forgot, I have relatives in Washington...

Witches? Hmmm.... I'm an eccentric left-handed, freckled, redhaired woman, and I dont go to church, like to wear black and am overly fond of cats. Guess it's a good thing I dont live in Salem with my cousins, I'd be burned at the stake.

Originally Posted by dannmarr

Before I purchase a cooler...

If I'm not too late to offer some advice...

You have two options. You can get a standard cooler that fits (about $75) and install it between the radiator and the air conditioning condenser. There is a photo of such an installation at this link:
http://www.drwtransmission.com/image...oler_local.jpg

Or, you can pay $130 to get one that has a built-in electric fan and install it
behind the driver's side fender wall. I attached a photo of such an
installation. You can buy that cooler here:
http://www.alamomotorsports.com/pmc/Cat_page13-1.html

The model you want is either 12511 or 12515.

IMPORTANT: Be sure to bypass the radiator's cooler when you install it!!!
Do not make the mistake of installing it in series with it, as is the typical
configuration for other cars!

Good luck!
~ Rad

[dcarrb]

Originally Posted by radsvx

IMPORTANT: Be sure to bypass the radiator's cooler when you install it!!!
Do not make the mistake of installing it in series with it, as is the typical
configuration for other cars!

Many here will disagree with that bit of advice, myself included. A supplemental cooler's function is to prevent high ATF temps. Bypass the radiator and the fluid may never reach proper operating temperature, delaying or preventing torque converter lock-up. You don't want it hot, but you DO want it to reach normal operating range.

If you're running a '92 with the original radiator you should install a filter upstream (if there's not one there already) to prevent possible clogging of the screen inside that model year's radiator cooler.

dcb

[kuoh]

And what happens if it doesn't, as often as it used to? Mine has been bypassed for about 5 years now and the tranny is still running the same as before, if not better. I can't say the same for the gas mileage, but I feel much more secure driving around a tranny that doesn't start slipping when it gets hot out. It may not be a good option for someone who lives up north, but here in KC and further south, I don't see it as a problem.

My tranny temps hovers at 160ish on the highway on warm summer days and doesn't lock up until the outside temps get well into the 90's. In heavy stop and go traffic, it can get up to 190 or so, but cools down quickly once the car gets going again. In the winter, it struggles to break 110 degrees when it's below freezing outside, but still drives just fine. I was expecting to replace the tranny 5 years ago, so personally, I feel that the lower temps will help protect the tranny more than having the TC lock more often.

KuoH

Originally Posted by dcarrb

You don't want it hot, but you DO want it to reach normal operating range.

[mbtoloczko]

Originally Posted by kuoh

And what happens if it doesn't, as often as it used to? Mine has been bypassed for about 5 years now and the tranny is still running the same as before, if not better. ...

You are right that its not going to damage the tranny, but in terms of driving experience, I'd much rather have the tranny operating at normal temperature ranges. I used to have an ATF cooler in series with the radiator cooler. I was always annoyed by the TC locking/unlocking in the winter time because the ATF wasn't quite heating up enough. I ended up installing a bypass thermostat so that the ATF would reach proper temperature in the winter. In the summer I was still able to maintain ATF temperatures of less than 190F except in the worst of situations (100F temperatures climbing a fifteen mile long 6% grade). With better placement of the auxillary ATF cooler and still using the radiatior cooler, I think I could have controlled the ATF temperature to within 160-175F at all times.

[JIMSVX]

Originally Posted by dcarrb

Many here will disagree with that bit of advice, myself included. A supplemental cooler's function is to prevent high ATF temps. Bypass the radiator and the fluid may never reach proper operating temperature, delaying or preventing torque converter lock-up. You don't want it hot, but you DO want it to reach normal operating range.

dcb

That's exactly where I'm at, nice cool oil, with only the supplemental cooler, but the TC never locks up. And in the St. Louis heat that is pretty amazing.

But I agree with mbtoloczko, "......in terms of driving experience, I'd much rather have the tranny operating at normal temperature ranges." So I'm going to keep working on the problem. What would be nice would be a 165 deg thermostatic switch which would switch in a by-pass around the stock cooler when the oil reached that temperature. You would think that would hold it at the ideal operating temperature.

- Jim

[dcarrb]

I guess a question that bears asking is, are you really prolonging the life of your transmission by running a setup which prevents the ATF from reaching normal operating temperature and wastes fuel as a result?

If your answer is yes, then more power to you.

dcb

Originally Posted by dcarrb

are you really prolonging the life of your transmission by running a setup which prevents the ATF from reaching normal operating temperature and wastes fuel as a result?

What is your opnion of the new aluminum radiator with the "better" cooler built inside of it? Do you feel that the ATF doesn't reach optimal operating temperature with it?