Transmission Cooler

[marco10]

Hello guys. Looking to install a tranny cooler. I was wondering if this job is easy enough to do it myself. I have a 2003 Astro. Thanks.

[LiftedAWDAstro]

It is a very easy job. I will be adding one to my '03 as soon as the weather cooperates. I am using a True-cool 11"x11"x1.5" stacked plate cooler. You will need to remove the grill and may have to make some brackets work. I did this on my 98. Here are the pics showing the location:

[marco10]

I was asking around some shops for a quote on getting my tranny cooler installed for me. What kind of prices and time should I be looking at? I figure it won't take more than 1.5 Hrs. Anybody know how long the installation should take?

[Water Boy]

Lifted put his (w/fan) in front of the rad so no rocks will hit it.

If rocks are not a problem, get the largest stacked plate with its own fan. You can mount it next to the transmission under the floor out of the way.

As for install $? Ask around for some backyard guys or a local independent trans shop. Stay away from chains/franchised shops.

Of the 100 people you know, there has to be someone that can do it for you for beers and a steak.

Keep us posted.
Pics are encourage.

[LiftedAWDAstro]

I originally had mine mounted there to use the airflow from the clutch fan. I later removed the A/C condenser because I didn't use A/C and I converted to on board air. Once I did that I installed the 12" fan behind the cooler for extra cooling capacity. Figure about 2 hours if you take your time.

[9dawgs]

I later removed the A/C condenser because I didn't use A/C and I converted to on board air.

Man, I wish I could say that. I just had my compressor replaced because I DO use my A/C. It gets hottttt down here in the swamp... This is a good topic, I'm thinking of installing a tranny cooler now due to the bigger tires I just installed. I think I need to let the old check book cool off for a bit though.

[LaGrasta]

I just installed the very same Tru-Cool unit this past weekend. It was very easy and not nearly as messy as I thought it was going to be. Easily less than 2 hours tops.

Instructions called for:
Trans–radiator–TruCool–Trans

It was so much easier plugging into the lower radiator line.
Trans–TruCool–radiator–Trans

No harm from what I gather however I run the risk of not cooling the fluid to the max as the radiator may be adding heat before it feeds back into the tranny. Thoughts?

[Water Boy]

Unless you are an Ice Road Trucker
http://www.history.com/minisite.do?cont ... i_id=54692

Run the TruCool after the radiator.

[dragonvan]

Go to my Mods list or my Transmission Cooler install to see mine. I even have a link on my mods list page for a decent place to get the Tru-Cool coolers. The 4490 comes with the correct adapters needed for the late GM fittings on the radiator so you don't need to buy those separate if you get one of the Tru-Cool's.

Definitely tap into the top trans cooler line at the radiator. GM only recommends installing the cooler after the fluid flows through the cooler inside the radiator. I have pics at the above links.

[LaGrasta]

Mine is working just fine, but I will take the effort and swap it.

[LaGrasta]

update, I finally swapped it.

[SafariRob]

I just installed the very same Tru-Cool unit this past weekend. ...It was so much easier plugging into the lower radiator line.
...No harm from what I gather however I run the risk of not cooling the fluid to the max as the radiator may be adding heat before it feeds back into the tranny. Thoughts?

LaGrasta, I didn't see your message when you originally posted it. This topic of where to place the external transmission cooler--before the radiator tank cooler or after, or even if the radiator tank cooler is used at all-- is one that I've wondered about, too.

I looked all over the net for a definitive answer, but found nothing conclusive. Of course, I found the usual people who felt that their way was best, even to the point that they were ready to flame anyone who thinks otherwise.

My own thoughts: It's probably six of one or a half dozen of the other as to which way is best. The transmission really creates a lot of heat when it's not in 4th gear and the torque converter clutch locked. I've wondered if the external cooler wouldn't be better used to remove the transmission heat before the radiator cooler had to deal with it. Seems to me that the engine would be better served for cooling reserve with this method as the radiator wouldn't have to deal with dissipating the extra heat. Some also like this way as the radiator temperature possibly preheats the transmission ATF to an optimum operating temperature before the ATF returns to the transmission.

Then there are others who feel that the external cooler should be placed after the radiator cooler. The thought here is that much cooler ATF is flowing back to the transmission. It's a closed loop after all; heat removed anywhere in the loop is a benefit to the transmission and the heat load on the radiator.

As for me, I think having an external cooler that is big enough to handle the transmission's heat by itself is the way to go. I have no data to support this thought, but I just don't like the idea of the radiator, whose primary job is to cool the engine, having to deal with the heat load of the transmission. I also like the idea that there can be no mixing of ATF and engine coolant if the radiator tank cooler fails and splits open. True, you rarely hear of that happening, but it can never happen if the two are kept separate.
But what of an optimal temperature for the transmission? There must be one, though I've yet to see it in print definitively. I know with the transmission in my van that the shifting is more abrupt when the transmission is cold in the winter. But even though the transmission temperature gauge doesn't get over 100F, the shifting becomes normal after a few blocks of driving.

My opinion at this point: Install the external cooler in whatever way is easiest for you. However you choose to do it, the cooler will work wonders keeping the transmission from overheating.

[LaGrasta]

thanks for your thoughts Rob. I'm about to do a C4 swap on my 1963 Ford Falcon. At present, I'm not running an extra cooler, but will definately add one with the swap.

As for my van, it is now installed after the radiator and seems to be working great. I'm not planning on touching it unless I have to. Thanks again for all the great feedback.

[LiftedAWDAstro]

I made this thread a sticky and will be adding the trans cooler install, temperature gauge and results in this thread. The cooler is installed in my old 2003 AWD and is done in the 98 SPB the same way.

The cooler I used is a Tru-cool LPD4590. I bought mine from Oregon Performance Transmission on E-bay for around $85 shipped. It included ALL needed brackets, hoses and fittings.

Remove the grill...



Locate the upper tranny cooler line at the radiator tank...



Bend and cut the supplied brackets as needed for mounting. Remember to keep the cooler a few inches from the A/C condenser...



Disconnect the upper tranny cooler line at the radiator. This is the outlet line that goes back to the tranny.



Connect the hoses to the aux cooler with the supplied worm clamps.



Connect the top hose of the aux cooler to the metal line going back to the tranny and the bottom hose to the radiator port using the correct supplied fittings and hose clamps.



Put everything back together and start up to check for leaks. Once you run it for a little bit check the fluid level as it will be down a quart or so.

[LiftedAWDAstro]

Tranny temperature gauge installation. (these pics are from the SPB but the 03 was done the same way)

Located the test port on the 4L60E. It is located on the driver side to the front of the gear shift electrical connection.





Now remove the 1/8" NPT plug and screw in the brass sensor. DO NOT use Teflon tape as you may not have a ground connection. The sensor is more or less reading the case temperature but it gives a great idea on what the temps are doing. Run the sensor wire up to where ever you are going to mount your gauge. I mounted my Autometer gauge in a pod on the A-pillar.



Now for some aux cooler tests. The test was done on the 2003 AWD and was done when we drove it to trade in on our truck. The tranny was in perfect shape...new Amsoil synthetic fluid and filter, Transgo HD-2 shift kit and Corvette servo. There was NO slip in the tranny!!!! The day was in the mid 70's and wasn't too humid out. With the aux tranny cooler installed the tranny temp would never get above about 150 - 165 no matter where we drove or how fast. This is without towing. The day we traded the van in, I removed the aux cooler and on the drive to get the truck, the tranny easily reached the 180 degree mark within about 10 miles of driving. This was from a cold start! The final temp once we arrived at the dealer (40 mile drive, mostly interstate) was around the coolant temp of 195! This is a 30 to 45 degree difference with just the aux cooler plumbed after the stock cooler. No wonder we would see 210 towing our camper and that was babying it. I can't even imagine how hot the tranny would get with no aux cooler! My final suggestion for long tranny life is synthetic fluid and a massive tranny cooler!