Best auxilliary trans cooler for crowded area ahead of radiator

TitanMike · 08-07-2017, 12:09 PM

My tow vehicle is a Nissan Titan and I'm towing a 2018 Flagstaff Micro Lite 25 BDS.

Total combined weight with all gear aboard fuel and and water tanks full (ex. holding) is 11,980. Well under the door sticker capacity of the Titan of 15,500 (6k for truck, 9500 for towed vehicle).

When in the mountains and traveling at speeds below converter lock in 4th Gear the trans heat climbs fairly high. A downshift to 3rd gear drops the heat to the middle of the trans temp gauge.

I am a firm believer that one can't have too much cooling for transmission fluid with the exception of freezing weather. (easily fixed with a thermal bypass valve). I would like to keep the trans fluid temp down around 165/170 degrees so am planning on adding a third cooler to the factory complement of a liquid/liquid cooler in the radiator and a liquid/air cooler they have sandwiched between AC condenser and radiator.

My issue centers on the fact that there is a P/S cooler and auxiliary fan ahead of the A/C condenser along with a horn. Has anyone else here mounted a larger cooler like a Tru-Cool Max 4739 in the remaining space between grille and AC condenser on a Nissan Titan?

Or perhaps a cooler with thermostat and fan mounted elsewhere like perhaps one of the Fog Light openings in the bumper/valance?

Plenty of power and transmission isn't showing signs of "Heat Stress" like burned fluid or funny shift behavior but I want to build some margin int the tranny cooling system.

Any suggestions? Favorite cooler? Experiences?

BTW, not really interested in Hayden coolers. Had my experiences with them and am looking at the Tru Cool or Derale brands, Derale offers some nice integrated units with cooler, fan, thermostat, that are both high flow and compact.

A32Deuce · 08-07-2017, 12:33 PM

There are other coolers that are tubes with fins. Do not need to be in front of the rad. and can be mounted to the frame under neath. They act as a giant heat sink. Use them in Hot Rods to keep trans. temps in check. They do work!

A32Deuce · 08-07-2017, 12:34 PM

No fan needed. Sell by weight of vehicle.

TitanMike · 08-07-2017, 12:49 PM

I've considered mounting one underneath but since the Titan is 4WD there isn't much room until you get back to the area near the muffler.

The length of hose would add more flow restriction than I'm willing to add.

I really want to add something up in the cool air stream. Ideally I'd find a couple of tube/fin coolers that are about 6" square. Mount one on each Fog Light opening and hook in series. Fresh air with nothing behind. Openings are 5" in diameter.

A32Deuce · 08-07-2017, 02:43 PM

You could make that first stop out of the trans.

Lawrosa · 08-07-2017, 03:21 PM

Looks like you have plenty of room up front for a cooler added in. A lot of guys look like they are removing the electric fans. Not sure if there is also a clutch fan.

This guy removed the electric fan but I would think you can get a cooler on the upper radiator.

Myself I would leave the electric fan alone.

Myself on my chevy I added a cooler as big as I could fit next to the factory small cooler and spliced in series. I run 165F towing 6000 lbs in 100 f outside temps @ 75 mph.

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IMG_3009 by lawrosa, on Flickr[/IMG]

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IMG_3303 by lawrosa, on Flickr[/IMG]

babock · 08-08-2017, 01:31 AM

The 40K Tru-Cool is an awesome cooler . I installed one on my Silverado 1500. I made up stainless steel lines for mine. Pulling my 7k boat, my trans fluid never got above 190 pulling up to Lake Tahoe.

Lawrosa · 08-08-2017, 02:03 AM

[QUOTE]

Quote:

Originally Posted by babock

The 40K Tru-Cool is an awesome cooler . I installed one on my Silverado 1500. I made up stainless steel lines for mine. Pulling my 7k boat, my trans fluid never got above 190 pulling up to Lake Tahoe.

Trouble with that tru cool that I was aware of was feeding a plate fin cooler from the bottom. I assume trapped air at top will reduce the cooling of that cooler.

There was no neat way to run the lines up and flip the cooler.

This is why I mounted the second cooler side ways. Feeds from bottom up and out.

But you came up with a good solution with the flex lines. If it were me I would flip it with the ports on the top..

Because of mounting issues use standoffs from the home store. They are nylon... Thats what I did with mine..

babock · 08-08-2017, 02:33 AM

[QUOTE=Lawrosa;1587391]

Quote:

Trouble with that tru cool that I was aware of was feeding a plate fin cooler from the bottom. I assume trapped air at top will reduce the cooling of that cooler.

There was no neat way to run the lines up and flip the cooler.

This is why I mounted the second cooler side ways. Feeds from bottom up and out.

But you came up with a good solution with the flex lines. If it were me I would flip it with the ports on the top..

Because of mounting issues use standoffs from the home store. They are nylon... Thats what I did with mine..

I did read many people's same opinion on that but everyone I saw mounted it with the hoses at the bottom which is also tru-cool's recommendation.

These coolers have bypass channels at the top of the cooler which are wider channels and allow flow through them instead of the thinner lower ones when the fluid is cold. That may be why they don't get air at the top. The air would get purged.

It does work extremely well. Has reduced temps tremendously. My 1999 didn't even come with the tiny GM cooler even though it had a trailer package. Apparently, they didn't add that until a later model year. 1999 was the first year of the body style which is also like yours.

larry pw · 08-08-2017, 09:03 PM

Whatever type you choose or where you locate it,run the tranny fluid to the aux cooler first, then to the existing cooler. You will remove more heat from the tranny fluid and reduce the heat load to the engine coolant.

babock · 08-08-2017, 11:41 PM

Quote:

Originally Posted by larry pw

Whatever type you choose or where you locate it,run the tranny fluid to the aux cooler first, then to the existing cooler. You will remove more heat from the tranny fluid and reduce the heat load to the engine coolant.

If you are keeping the radiator cooler like I did, you run it to the radiator cooler first and then the auxiliary cooler. This is the directions for many of the coolers including the Tru-cool that I bought.

Lawrosa · 08-08-2017, 11:46 PM

Quote:

Originally Posted by babock

If you are keeping the radiator cooler like I did, you run it to the radiator cooler first and then the auxiliary cooler. This is the directions for many of the coolers including the Tru-cool that I bought.

Agreed.. Always keep the rad cooler or you'll have issues in the winter. The rad is what will warm the tranny up.

Also you want to flow through rad cooler first. Then aux coolers back to trans.

If it was the other way the rad would just reheat what you are trying to cool. That would be counter productive and inefficient.

babock · 08-08-2017, 11:53 PM

From the Tru-cool literature:

http://media.spicerparts.com/cfs/fil...store=original

Quote:

Install the cooler in series and downstream of the radiator in-tank oil cooler. This maximizes heat transfer and decreases transmission warm-up times in colder weather. Most OEM installations are plumbed this way.

Quote:

How should I mount the oil cooler fittings?
Fittings can be located up, down or sideways. This advantage, plus their compact design, makes installation of our coolers quick and easy

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