Thread: Want To Add Trans Cooler

Originally Posted by rottonj

My LS4 stays that cold in the cold of winter(110 to 120 degrees 45 minute commute), Hayden 679 trans cooler inline with the factory cooler. Average summer temp is around 180, before the cooler was added it would reach 220 easy. I don't drive it in the winter anymore, but those temps were too cool in my opinion .

I never drove my GXP in the snow/frigid cold...so I just know in the Missouri heat/humidity it never saw 190* again, let alone it barely crept over 180* beating on it all afternoon.

Originally Posted by rottonj

My LS4 stays that cold in the cold of winter(110 to 120 degrees 45 minute commute), Hayden 679 trans cooler inline with the factory cooler. Average summer temp is around 180, before the cooler was added it would reach 220 easy. I don't drive it in the winter anymore, but those temps were too cool in my opinion .

Thanks for giving a real world example with the LS4 and the 4T65E-HD tranny with a trans cooler. As stated earlier if you size the cooler (S) to the heat reduction required with a proper installation, any transmission will see a dramatic reduction in temperature regardless of the engine in front or along side the tranny. I looked up the GVW rating of your tranny cooler which is 30,000 GVW (decent size BTW) but you could easily see another 30 degree in drop in the summer by separating the tranny cooler from the in radiator cooling, and allowing the tranny cooler to do all the cooling like it does in my 3 cars. My guess is that the average coolant temp for that LS4 V8 if similar to other GM V8's like my LS7 is about 210 degrees. The reason the tranny temps are so high on stock trans radiator cooled LS4's is that the very hot tranny fluid is attempting to be cooled by coolant that is 210 degrees.....WAY TOO HIGH AND HOT. The ideal tranny temp despite what is often published is not around 180 degrees. it is around 140 degrees for all year round driving but often difficult to achieve with just 1 cooler ( I have 2 Long Dana coolers on my GP and 2 coolers on my Mustang GT as well outside of the radiator cooling...stand alones). You could easily drop another 30 degree reduction with your setup if you allow the Hayden cooler to do all the trans fluid cooling outside of the radiator.

My 01 GP has 205,000 miles on the tranny with the 2 coolers doing all the cooling outside of the radiator and I drive the car all year round in VERY cold weather. The only issue in very cold weather is that the tranny needs about 3 miles of gentle driving when below 20 degrees outside to shift in OD since the fluid takes longer to heat up under those conditions....well worth this minor delay. The Long/Dana coolers with built in temp control never let the fluid drop below 120 degrees. If you do not drive the car in the winter anymore, I certainly would have the cooler as a stand alone outside of the radiator since 180 degrees in the summer is still too high, in my opinion based on 35 years of adding coolers on my personal cars...........The number #1 killer of any transmission is HEAT followed by dirt (change the fluid/filter often @20,000 mile intervals and the 4T65E will live a long life.)

Originally Posted by jbamonte

Thanks for giving a real world example with the LS4 and the 4T65E-HD tranny with a trans cooler. As stated earlier if you size the cooler (S) to the heat reduction required with a proper installation, any transmission will see a dramatic reduction in temperature regardless of the engine in front or along side the tranny. I looked up the GVW rating of your tranny cooler which is 30,000 GVW (decent size BTW) but you could easily see another 30 degree in drop in the summer by separating the tranny cooler from the in radiator cooling, and allowing the tranny cooler to do all the cooling like it does in my 3 cars. My guess is that the average coolant temp for that LS4 V8 if similar to other GM V8's like my LS7 is about 210 degrees. The reason the tranny temps are so high on stock trans radiator cooled LS4's is that the very hot tranny fluid is attempting to be cooled by coolant that is 210 degrees.....WAY TOO HIGH AND HOT. The ideal tranny temp despite what is often published is not around 180 degrees. it is around 140 degrees for all year round driving but often difficult to achieve with just 1 cooler ( I have 2 Long Dana coolers on my GP and 2 coolers on my Mustang GT as well outside of the radiator cooling...stand alones). You could easily drop another 30 degree reduction with your setup if you allow the Hayden cooler to do all the trans fluid cooling outside of the radiator.

My 01 GP has 205,000 miles on the tranny with the 2 coolers doing all the cooling outside of the radiator and I drive the car all year round in VERY cold weather. The only issue in very cold weather is that the tranny needs about 3 miles of gentle driving when below 20 degrees outside to shift in OD since the fluid takes longer to heat up under those conditions....well worth this minor delay. The Long/Dana coolers with built in temp control never let the fluid drop below 120 degrees. If you do not drive the car in the winter anymore, I certainly would have the cooler as a stand alone outside of the radiator since 180 degrees in the summer is still too high, in my opinion based on 35 years of adding coolers on my personal cars...........The number #1 killer of any transmission is HEAT followed by dirt (change the fluid/filter often @20,000 mile intervals and the 4T65E will live a long life.)

Yup; Mine bypassed the radiator as well.

Still wasn't anywhere near 140* in real world driving in the Midwest.

LS4 Nation on facebook?

LOL.

97% of those people think the LS4 is made of gold so this is coming from Triple Edge; someone who BUILDS the transmissions that the 4590 is PLENTY for the car.

The 4590 shows as being 48 plates, gvw 28,000, and shows a picture of a truck towing a triple axle trailer. I'd say it is more than enough.

http://www.trucool.com/products/tru-cool-lpd

Trust me; it'll work just fine.

The people that tell you it's too small apparently don't understand how common sense works.

Actually; the target temperature for the 4T65E to prevent any premature damage is 170* (from GM). Anything less is just like revving a cold engine. 140-160 is too cold.

I guess my tranny @ 205,000 miles on it has been operating like a cold engine for the last 115,000 miles with the 2 Long/Dana coolers hooked up. The trans fluid rarely gets above 140 degrees. It shifts today like it will easily get to 250,000 miles. Hard to argue with success and real world experience....

You're one guy.

It's hardly a statistic by ANY means.

But; keep on acting like it matters and giving the OP bad advice

140* is to cold. The thermocoupler in the cooler is 180*. Running two coolers, well, they are just fighting each other.

I just programmed my fans to come on at 195. Everything reaches working temps in the winter at the same speed, but the coolant hits temp before the trans fluid in the summer kicking the fans on and keeps the trans always a few degrees cooler.

like he said, 140 is not hot enough. and hes right too, your 100% wrong here.

so take one extra cooler off the car.

theres a chart floating around with the optimal temps, and what happens to a cold or to hot tranny. you really want to be 170-190 ish

we are talking gm cars here are we not? not trucks/suv's made by who knows....

Don't mean to hijack, but my question is similar enough not to start a separate thread. I'm also interested in installing a transmission cooler setup to keep my trans at an optimum temperature, but my car has to deal with an extreme range of temperature. I live in AZ, and during the summer, the air temperature is regularly 95F+, with frequent trips climbing hills in 120+. I do not have an aftermarket trans temp gauge installed, but just crusing around this summer, the temp on the info center is usually maxed (I think at 197F?). In the winter here, temps get down into the teens. Are there any special considerations for my climate, other than what's already mentioned? The car is a factory-stock 08 GXP with 78,000 miles on it. I've only had it since March, and I've had zero problems with the transmission performance, but the fluid is already starting to turn brown. I want to keep this thing alive. Also of note, when climbing the steepest parts of my usual trip, the coolant gauge does tend to head near the red, even with the a/c off.