automatic transmission cooler..is it worth it?

[ckrocks]

is tranny cooler necessary for A/T cars with large performance gain(in both 4 banger and v6 trims)? is there even a company that makes a kit for 2003+ 9-3?

[cjhutch]

Easy answer is it won't hurt. Anything to make parts of your car run cooler is going to help. I'm sure you could just buy one of the universal tranny coolers and then have some lines made up. Just make sure you decide on where you are going to place it because you will want to get exact measurements.

[9-3gotboostAERO]

there is no kits being made. Im looking to do this by the end of the summer b.c. i dont trust my tranny holding more the 300hp...
Gonna have to fab it up myself it looks like.

[NickTaliaferro]

No real need to change the cooler. The integrated oil to water will do plenty. It also serves to warm the trans quicker on cold starts. The other issue is if you make the fluid too cold (Winter driving with no thermostat) you can cause the gearbox to go back to cold shifting patterns. Stock is fine.

[ckrocks]

thanks for all your input.

Originally Posted by NickTaliaferro

No real need to change the cooler. The integrated oil to water will do plenty. It also serves to warm the trans quicker on cold starts. The other issue is if you make the fluid too cold (Winter driving with no thermostat) you can cause the gearbox to go back to cold shifting patterns. Stock is fine.

Nick, I believe there are a number of people on this forum who have had their auto tranny replaced regardless of whether their cars are stock or modded. This led me to think that the 5spd auto in nature is pretty weak, but then i noticed in the other thread that the max torque tolerance on the box is quite high. What do you think might be the culprit in the failure if the torque limit is so high?

[9-3gotboostAERO]

O rings mainly. such a small part makes such a huge difference...

[smurkenstein]

Most of the transmission woes were with 03 (and some 04) cars with the coolant leak scenario - this should have been fixed in the newer cars

[Dach]

I had mine done, and no regrets. I used a generic Oil Cooler.
I didn't have to worry about warming up to ATF much. I'm from a much warmer climate.

You don't need to get too large a set up cause you don't want a huge pressure drop in the gearbox.

[ckrocks]

ah i see. thanks again everyone.

Dach, how hard was the installation? did you use existing coolant lines?

[Dach]

I didn't do it. From what I've seen, its relatively easy, but don't take my word for it.

[Nibiru]

Originally Posted by NickTaliaferro

No real need to change the cooler. The integrated oil to water will do plenty. It also serves to warm the trans quicker on cold starts. The other issue is if you make the fluid too cold (Winter driving with no thermostat) you can cause the gearbox to go back to cold shifting patterns. Stock is fine.

I don't think a cooler could hurt, especially if you do any modifications which increase horsepower.

[Cosmicflash]

Originally Posted by Nibiru

I don't think a cooler could hurt, especially if you do any modifications which increase horsepower.

I agree with Nick--no reason at all. Unless you have an used analysis that shows it's breaking down and is burnt don't bother. There have been virtually no issues with either of these trannys according to everyone.

If you're concerned change the fluid more frequently.

[Nibiru]

Here is a link.
http://www.supercheapauto.com.au/diy...ooler-kit.aspx

I have heard time and time again that lowering the tranny fluid by 10 degrees will double the life of your transmission. Though it isn't necessary, there is a benefit. And if you drive the car like I do then it is probably a good idea. Also with an auxillary cooler you would probably have to change the fluid less. I think eventually it would pay for itself, but to each his own.

And if Saab is like most other cars, the cars primary tranny cooler is in the radiator or cooled by the radiator fluid so making this cooler via an additive or using deionized water will help lower the temps.

[j-y]

Do I need to disconnect the original/existing cooling lines if I were to install a trans cooler?

[kimvette]

Originally Posted by ckrocks

is tranny cooler necessary for A/T cars with large performance gain(in both 4 banger and v6 trims)? is there even a company that makes a kit for 2003+ 9-3?

The conventional rule of thumb is for every 20º cooler the transmission runs, the service life is doubled. I don't know if that holds true for the latest generation of slushboxes.

[pugsaabaero]

i think this is a great idea hopefully someone has done this and can chime in also i heard that additives to the rad like water wetter gel up in there? thought about additive as a why not this sucker runs hot anyways.

[HuNtS]

I've never heard of anyone having tranny issues on here tuned or otherwise.. Keep the fluid in good shape, and make sure your radiator and coolant are up to par and you'll be fine.. I would spend my money elsewhere. Just my $.02

[mike saunders]

Originally Posted by Nibiru

Here is a link.
http://www.supercheapauto.com.au/diy...ooler-kit.aspx

I have heard time and time again that lowering the tranny fluid by 10 degrees will double the life of your transmission. Though it isn't necessary, there is a benefit. And if you drive the car like I do then it is probably a good idea. Also with an auxillary cooler you would probably have to change the fluid less. I think eventually it would pay for itself, but to each his own.

And if Saab is like most other cars, the cars primary tranny cooler is in the radiator or cooled by the radiator fluid so making this cooler via an additive or using deionized water will help lower the temps.

This was definitely true when autoboxes without auxiliary cooling were installed on trucks and other tow vehicles...and transmissions had to be changed every few seasons.

Things have come a loooong way since those days, with most manufacturers installing auxiliary coolers from the factory on vehicles that need them.

[jmcdoogie]

Originally Posted by kimvette

The conventional rule of thumb is for every 20º cooler the transmission runs, the service life is doubled. I don't know if that holds true for the latest generation of slushboxes.

I've read that too. But 20deg lower than what? i.e. what's the optimum temperature to run the ATF at? I've ALSO read you don't want to get crazy with it until it warms up.
In fact, step back for a moment and consider what's really going on. The Saab Workshop Manual considers "normal operating temperature" 70deg - 80deg C (or 145deg - 160deg F).
Well, the problem as I see it is, the Coolant in the Radiator runs 25deg C (40deg F) hotter than that. So, maybe the ATF is actually helping cool the Engine Coolant in the Radiator !?!?! i.e. - the ATF is running at about 100deg C (210deg F) at it's coldest
I sure hope that wasn't the intended effect.

So, are we suggesting that lowering the ATF Temp 20deg means lowering it's operating Temp to 75deg C (150deg F) ?
Or is there a different "magic" temperature for optimum Tranny life that we're trying to hit?

I have been talking about installing a big fat external ATF Cooler in the past on this Forum. But, I'd like to know IF my ATF is running hot first, and by how much. Does anyone know, is there an ATF temp sensor already in the Tranny that I could log from the OBDII port?

BTW, I did my first "mini-flush" of the ATF at 23,000 miles a couple weeks ago, and it was burnt - not horrific, but burnt. (this was after I did a "spirited" 500mile romp to Hermiston, OR and back from Issaquah, WA, including a 100mph+ leg from Prosser to Paterson the full length of Hwy 221) When I got back, I changed out only 4 Litres of ATF, but I felt like it made a slightly noticeable difference in shifting smoothness, particularly when downshifting when cold (which is most of the time out here in "The Land without Summer") So, I'm going to change out another 4 Litres this weekend, try to freshen the ATF up as much as practical.

Again, what is the ideal ATF Temp?

[Jn2]