Use BOTH trans coolers, or just one?

[Mrturner1]

Ok so I'm wondering how to go about cooling my trans but also worried about having too many fittings/bends/clamps. My radiator has a built in trans cooler with hard lines and cools the th400 just fine. Temp never goes above 140 even uphill when it's 75* outside. I added a B&M Holeshot 3000 converter and still it never goes above 150* while driving around. I decided to try and launch it, footbraked it to around 3000rpm and held that for a couple seconds and then let and launched. I went through 1st and 2nd everything went great (besides traction which I have none of now with the converter and mini spool lol) and I cruised it on home watching the temps. Engine temp quickly went back down to 185* like it always does, but the trans temp went up to 200*-205* and it stayed there all the way home which was about 5 minutes. Right after the hard launch when I stopped to check the gauges and make sure nothing went wrong, the trans temp spiked just for 30 seconds or so to 210* and then went down for the drive home.

It seems like the built in cooler in the radiator is good enough unless I'm foot braking real hard, but I want to get the trans cooling a little more stable than that, and maybe not see quite as high of spikes after hard launching.

My options are add a plate style cooler and mount it in the front of the radiator, and tie it into the system with the built in cooler. This is the option I was talking about when I mentioned having to many fittings and clamps because that's more parts to fail or leak and have something go wrong.

Another option would be just have a big plate style cooler and either mount it in front of the radiator, or somewhere under the bed with a small auxiliary fan mounted to it. It seems I would also gain more fluid capacity by mounting a plate cooler in back somewhere, because I'd have about 12 more feet of line.

What do you guys with big stalls run in yours? And what are your temps cruising and when foot braking or driving it hard?

[Valarius_Starchaser]

With a secondary cooler installed in normal driving you would run TO COLD 210 is a little hot I recommend you read up on what a torque converter works and what happens when you launch hard like that seeing a temp that high after a launch that hard isn't that unheard of but at the same time shouldn't be taken lightly as in (don't drive like that all the time) because anything over 190* will drastically reduce the lifespan of the frictions inside of the transmission if it is constantly subjected to those temperatures

Thats just my school of thought and I look forward to what others have to say

[WorkinLonghorn]

I agree with Valarius. A few seconds at 210 after full throttle conditions I wouldn't worry about.
There are these graphs that have been around forever used by shops to sell aux. coolers. I don't know if there is any truth to the estimates, but here is the first one I ran across in a search;

http://www.txchange.com/heatchrt.htm


Now if you were towing and you saw continued 200-220+ then I would get a cooler.
In the shop we used to put the aux. cooler before the standard radiator one so that the temperature was in normal range. -WL

[firedemon]

I agree with workin longhorn I was always told put the aux in line before the radiator that way the radiator could regulate the temp better ie too cold it will bring it up to coolant temp too hot the opposite

[Mrturner1]

The part that concerns me is the temp stayed around 200-205 for a while. It didn't cool back down like the engine did. When I'm driving it normally it never goes over 150* including up long hills. I can understand the spike because of the friction when stalling it out like that, but I'm wondering why it didn't come back down after driving it normally again?

[Valarius_Starchaser]

Transmission fluid isn't going to dissipate heat as fast as coolant for a few reasons one being the fact that it's petroleum based and not H20 also think of what the coolant has for a cooling system compared to the transmission

with anything over 200 for more then ten minutes and you should look into a cooler but with where your at I think it's fine you could mount and run an aux cooler in place of the radiator setup and see what happens but I would be willing to bet it would be the same OR worse then your current set up

[BrianG]

Originally Posted by Mrturner1

The part that concerns me is the temp stayed around 200-205 for a while. It didn't cool back down like the engine did. When I'm driving it normally it never goes over 150* including up long hills. I can understand the spike because of the friction when stalling it out like that, but I'm wondering why it didn't come back down after driving it normally again?

What were the driving conditions back to home? Were your fans running? Highway, stop and go, backroads?

[Mrturner1]

Originally Posted by BrianG

What were the driving conditions back to home? Were your fans running? Highway, stop and go, backroads?

Fans came on for a few minutes but shut off when the engine temp went down. The trip home was all winding back roads, nothing over 40mph and two stop signs

[Mrturner1]

Originally Posted by Valarius_Starchaser

Transmission fluid isn't going to dissipate heat as fast as coolant for a few reasons one being the fact that it's petroleum based and not H20 also think of what the coolant has for a cooling system compared to the transmission

with anything over 200 for more then ten minutes and you should look into a cooler but with where your at I think it's fine you could mount and run an aux cooler in place of the radiator setup and see what happens but I would be willing to bet it would be the same OR worse then your current set up

I was wondering about that, if a plate style cooler by itself would be better or worse than the built in rad cooler. I have no idea the capacity of the cooler in the radiator though

[Valarius_Starchaser]

I think it would hold our temp equal when driving due to wind passing over the aux cooler but due to no coolant in the vicinity of the trans fluid like in the radiator cooler I think you would see higher temps on hotter days and when moving slower I also believe your temps would drop slower I am sold on the internal radiator trans fluid coolers are superior in nearly every way to external units

[BrianG]

I would add a good quality plate cooler in line with the in-radiator cooler. Then I'd figure out a way to be able to manually turn on the fan that is behind the plate cooler. That would allow you to force it on in slow traffic.

[Valarius_Starchaser]

Originally Posted by BrianG

I would add a good quality plate cooler in line with the in-radiator cooler. Then I'd figure out a way to be able to manually turn on the fan that is behind the plate cooler. That would allow you to force it on in slow traffic.

good point on the manual override switch MrTurner if you haven't done so already I would recommend it heres a wiring diagram that shows how to wire the override switch pretty simple the hardest part is mounting the switch where you like it and getting the relay in a half decent location

[Mrturner1]

Originally Posted by Valarius_Starchaser

good point on the manual override switch MrTurner if you haven't done so already I would recommend it heres a wiring diagram that shows how to wire the override switch pretty simple the hardest part is mounting the switch where you like it and getting the relay in a half decent location

I do have a manual switch for the electric fans for radiator cooling but I don't have a small fan yet. It might be time for a plate cooler and fan

[BrianG]

Originally Posted by Mrturner1

I do have a manual switch for the electric fans for radiator cooling but I don't have a small fan yet. It might be time for a plate cooler and fan

Put your plate cooler in front of the radiator. That way it will work while you are driving without needing the fan on (unless the trans or coolant is really warm). Also, then you won't need another fan since you already have the electric fans for the radiator. They really are not that big. It won't block that much air flow to the radiator... not enough to be an issue anyhow.

[toolboxchev]

Originally Posted by Mrturner1

Ok so I'm wondering how to go about cooling my trans but also worried about having too many fittings/bends/clamps. My radiator has a built in trans cooler with hard lines and cools the th400 just fine. Temp never goes above 140 even uphill when it's 75* outside. I added a B&M Holeshot 3000 converter and still it never goes above 150* while driving around. I decided to try and launch it, footbraked it to around 3000rpm and held that for a couple seconds and then let and launched. I went through 1st and 2nd everything went great (besides traction which I have none of now with the converter and mini spool lol) and I cruised it on home watching the temps. Engine temp quickly went back down to 185* like it always does, but the trans temp went up to 200*-205* and it stayed there all the way home which was about 5 minutes. Right after the hard launch when I stopped to check the gauges and make sure nothing went wrong, the trans temp spiked just for 30 seconds or so to 210* and then went down for the drive home.

It seems like the built in cooler in the radiator is good enough unless I'm foot braking real hard, but I want to get the trans cooling a little more stable than that, and maybe not see quite as high of spikes after hard launching.

My options are add a plate style cooler and mount it in the front of the radiator, and tie it into the system with the built in cooler. This is the option I was talking about when I mentioned having to many fittings and clamps because that's more parts to fail or leak and have something go wrong.

Another option would be just have a big plate style cooler and either mount it in front of the radiator, or somewhere under the bed with a small auxiliary fan mounted to it. It seems I would also gain more fluid capacity by mounting a plate cooler in back somewhere, because I'd have about 12 more feet of line.

What do you guys with big stalls run in yours? And what are your temps cruising and when foot braking or driving it hard?

After running mine hard for 10 years with both of em, last summer I was getting an overheating problem in my cooling system. It almost cooked my transmission. I now have the auxiliary cooler running by itself.

The one thing I have yet to rebuild is the transmission it has outlasted most everything else on the truck, turbo 350.

That should say something about those transmissions.

[un4gvn!]

If you are going to wire up a toggle switch, use a toggle that has a light indicator built into the toggle. A little light will come on at the tip of the toggle when you turn on the fan. A lot less wire and drilling to mount a separate light. A lot cleaner look.