[ARCowboy]

Easy Modification, Maximum Cooling.

For maximum effect with minimal effort, cut the stock return line in the short rubber portion near the radiator outlet on the driver side.

@Limptriscuit has an excellent post on this method here
Inexpensive trans cooler install | Chevy Colorado & GMC Canyon (coloradofans.com)

Several others have done similarly great installs and posted pictures in many threads like our fearless admin/mod, @DieselDrax

• Limptriscuit installed a non-fan Derale 13503/33503 Plate and Fin Cooler
• If you are using 4x4LO or towing heavy in stop/go traffic, you may want a 12v fan to help cool the fluid and should opt for Derale 13750 Cooler with Derale 13021 -6AN x -6AN In-Line Fluid Thermostat and Derale 16763 Electric Fan Relay Wire Harness.

This picture is of the entire line setup where I had to cut them to remove them, but removal is not possible/necessary for this. Only cut the drivers side return line !

Using either 3/8" barb splicers or a 6AN Flare to 3/8" Hose Barb, connect your aux cooler lines like this photo or however you see best. (not my photo, if this is yours please let me know so I can give you credit ! I saved it during my ordeal and do not recall where from). An EVIL ENERGY 6AN Line Kit w/10 fittings and 18" Heavy Duty Hardened Cable/hose Cutter should get you most of the way, if not all the way.

Those of us who have mounted Aux coolers have found the front grill bars a good place to do so with plenty of airflow, but feel free to get creative.

 

[ARCowboy]

Bulletproof Setup

Bulletproof setup takes a bit more work, but everything fit really nicely and can be done in your garage. The general process is:

1. Drain transmission
2. Remove OEM hardlines
3. Pressure test aux cooler !!!
4. Figure out where/how you are going to mount components
5. Attempt mounting them, find clever solutions to issues or choose different location
6. Actually mount components
7. Measure hose lengths
8. Pressure test hoses
9. Test fit and realize a hose is 1/4" too short
10. Make new hose
11. Pressure test hose
12. Find leak
13. Fix leak
14. Test fit
15. Undo hoses and Prefill hoses/aux cooler
16. Clean up spilled transmission fluid
17. Drop pain and replace transmission filter (How to guide here)
18. Clean up more transmission fluid
19. Test drive

The last part of the original lines can be used to interface with the radiator and save some time/money. This part:

Step 1
After draining trans fluid and wiggling, bending, and cutting the hard lines out, the first step is to install the Improved Racing FSC-165* Thermostat (or use a transmission adapter with built in thermostat from Improved Racing, P/N TGM-100-T2. It looks like it would fit).

I mounted mine on the lower front crossbar, in front of the rad/condenser. I used some 1/8" thick rubber to try and shock isolate it and prevent bubbles... not sure how successful that was considering it is mechanically connected via the self tappers and brackets, but eh.

Step 2
Next is to mount your ICT Billet 6LXX Billet Transmission AN adapter if going with remote thermostat. If using the adapter+thermostat, skip this step.

Step 3
Last to install is the aux cooler. Keep in mind if it has a 12v fan, it will electrical wires run to it (usually is pretty easy to zip-tie to the fluid hose). Those of us who have mounted Aux coolers have found the front grill bars a good place to do so with plenty of airflow, but feel free to get creative. CX Racing has some kits/brackets available but a Derale 13750 Cooler fits perfectly between the lower two bars for me, re-used a factory bolt on the top, and required drilling two bolts for the bottom in a sideways mount (with inlet on the top, outlet on the bottom, pretty ideal). Plan to add a Derale 16763 Electric Fan Relay Wire Harness near your battery, and Derale 13021 -6AN x -6AN In-Line Fluid Thermostat hanging off the inlet or outlet of the aux cooler.

Step 4
Using 550 cord, a string, whatever, measure the distance to where you are putting the thermostat (or aux cooler) from the trans adapter (or adapter+thermostat). I wish I could provide you with an exact length and technique here, but it will take some practice. Keep in mind the connector will add some length, and too long is better than too short ! I found that the original routing of the hard lines provided ample room for 8AN, but recommend people use 6AN. It's roughly the same size as the original lines and much easier/cheaper.

I made a guide on making AN hoses in your garage and pressure testing them here:
How To Guides How to make AN hoses - Aviator4x4

An EVIL ENERGY 6AN Line Kit w/10 fittings and 18" Heavy Duty Hardened Cable/hose Cutter should get you most of the way, if not all the way.

Step 5
Test fit everything and use the correct angle of AN fitting. Sometimes a 45, sometimes a 90, sometimes a 180.

Using either 3/8" barb splicers or a 6AN Flare to 3/8" Hose Barb, connect your aux cooler lines like this photo or however you see best. (not my photo, if this is yours please let me know so I can give you credit ! I saved it during my ordeal and do not recall where from).

Step 6
That's pretty much it. As long as your hoses are the correct length and hold pressure with no bubbles after being sprayed or submerged (and your aux cooling radiator !), then you're good to start re-assembling. This would be an excellent time to change your transmission filter, but if not, refill your trans and pre-fill the lines and radiator.

 

[ARCowboy]

This is literally what I've been working on getting the parts together to do. Only thing different, I'm going to so is add a racor transmission filter to it.

Awesome, glad to hear it ! Just added a bunch of pictures/details to the bulletproof setup if you were going to integrate a thermostat or switch to AN lines completely. Let me know if you have any questions ! Whole purpose of this thread was to have a central information place about putting aux coolers on the 2.8L.

I highly, HIGHLY, recommend you pressure test the aux radiator and all AN hoses before installation. I bought a CX Racing kit and had it entirely installed before finding out that it leaked... super frustrating. I also ended up remaking all the hoses that came with that kit since they didn't inspire confidence in their non-uniformity... Eventually I just decided to make my own complete setup and found that Derale 13750 cooler fit perfectly between those bars. I only had to drill 4 holes, 2 for the cooler and 2 for the thermostat. I used the original hard-line routing for the new AN hoses from the trans to the t-stat/radiator, but re-used the ends of the original lines into the radiator.

To their credit, CX Racing eventually replaced the radiator after 2-3 weeks, took them 3-4 days to respond to any email. I pressure tested the new one and all hoses, then sold the kit on here.

I made a guide on AN hoses on my website if interested. I list out how I pressure tested them as well and everything you'd need to do so (an air compressor and some AN plugs). Working on transcribing it to these forums to keep outside links to a minimum, but haven't got around to asking chatgpt to transcribe HTML to BB code lol.

How To Guides How to make AN hoses - Aviator4x4

This How To Guide will cover making AN hoses in your garage with common hand tools.

aviator4x4.com

 

[ARCowboy]

Unrelated to this thread, but I'll respond here since it is the first time I've seen you post it - nice website! As mentioned before, I find your write-ups to be extremely helpful. I prefer to use paper versions instead of following along electronically but there isn't an easy way to print a forum post here as a document . So, I copy/paste the text + photos into a Pages document, adjust the formatting, and create a PDF for print. But with your website, I just tell Safari to show Reader view and hit print.

I'll have to wait until you post more of the guides I want though, as I just finished creating a PDF for the MAF sensor : View attachment 471176

Thanks ! I'm glad you find them useful. Always nice to hear.

I enjoy making them but have been super busy with life and work lately, but will hopefully get to convert more soon.

 

[ARCowboy]

So, I think my plan is to install 6L, 8L & 10L Transmission Cooler Adapter with Thermostat (improvedracing.com) and order the hose/fitting kit like @ARCowboy linked above. I'll then remove the factory hard lines, insert the quick-connect barbs into the OEM cooler ports and cap them off so the OEM cooler doesn't get junk all up in it even though it'll probably never be used again, and then run new braided lines to connect directly to the AN lines in my pic that was linked above for Step 5.

If I had to do it again I'd just run the adapter vs messing with mounting the thermostat, but I had ordered the CX racing kit which came with an adapter and thought it would be more convenient to use that and a remote thermostat. Boy was I wrong haha. That aluminum AN wrench is worth the money, though you'll never use it again. You might be able to 3d print a temporary 6AN or 8AN wrench.

Well I broke down and ordered all my parts except the an lines and fittings for my setup. Ordered two weld in bungs to pick which one I like the best. The other I'll weld into my original oil pan and then sell on the forum to someone looking for a pan with a drain but doesn't want to spend a fortune. View attachment 471713
View attachment 471715
View attachment 471714

Exciting ! Please post some pictures on the forums ! Either here, your build thread, a how to, whatever. Looks like an awesome project

 

[ARCowboy]

Well my journey for drive train cooling setup has progressed. Picked up a new rivnut tool and nuts so I can build a bracket to hold my new cooler setup under the bed. I think I will just delete the factory water cooler and run strictly a air cooler setup. Sfltruck has his old pan on the way to me, so I can weld it up and a few more parts ordered to make it a clean install.

Rivnuts are handy for sure. I especially like them when I remember to put a dab of jb weld on the outside when putting them in ! Haha.

Can't wait to see pictures

 

[ARCowboy]

A lot of street mod trucks with ls setups mount the trans coolers in the back. I've done a few sets for customers actually and the area is a nice place to put it out the way and away from damage if you have a intercooler.
Did order a adapter for the trans to run full an lines from trans to cooler. Verified the same gasket was used as the 6 and 8 l80s View attachment 472593
View attachment 472592

It will for sure work

6L50 Cooler Inlet/Outlet Adapter Plate Comparison | Chevy Colorado & GMC Canyon (coloradofans.com)

 

[ARCowboy]

I got started on this project today and will have to wait until Tuesday to complete it. You know what they say about assumptions. Well, I assumed the Improved Racing thermostat block would have the outlets at the same position as the factory lines so I ordered the unit with 90-degree 6AN elbows. Turns out the thermostat outlets are actually facing forward and ~45-degrees from factory, so I ordered a straight 6AN flare to 6AN ORB union which will get here Tuesday. In the meantime, I got the factory lines out, the OEM cooler plugged off, and the Improved Racing thermostat installed. The rest shouldn't be too bad.

That thermostat is a worthy upgrade ! Especially since you live in a state with real snow/cold

 

[ARCowboy]

Thank you,
There is a kit? Do you have the picture or part number for the kit? Thanks again.

Hit this button good sir !

 

[ARCowboy]

I am seeing similar temps with the stock setup off-road and towing. The high temps, I believe, led to my transmission going out. I have the rebuilt transmission installed, and will be installing the Derale 13750 Aux Cooler with fan setup and deleting the factory transmission cooler. I feel that the factory cooler does not do a good job of cooling the fluid at all.

Dealing with this same kind of setup with Caterpillar diesel and allison truck... already looking at deleting that and moving to a thermostat + aux cooler only setup.

 

[ARCowboy]

Hey ARCowboy, I literally just installed this set up, I’m working on the ignition wiring for the fan relay. How did you wire yours? Did you tie directly into a fuse, if so which one? Or did you tie into something else? Thank you.

I tied mine directly (without relay) in to a Switch Pros SP-9100 8-Switch since I wanted the ability to turn it on or off for water fording. I have found installing a power distribution setup (like that SP9100, or Auxbeam 6 Gang Switch Panel BC60 are also popular on here) early on helps make any other mod easier since I don't need to mount a bunch of relays all over the place.

If you're only using it for relay triggering, EPAuto Tap-A-Fuse in F17 for 12v ignition sense should work. I used it when I wired the SP9100 in because I wanted the backlight to be dim 100% of the time (usually that wire is triggered off the headlights to dim the backlight, but the backlight was seriously bright).

 

[ARCowboy]

Hey guys, wondering if someone can answer a few questions to help those of us that are considering an aux transmission cooler. I wanted to thank everyone for all of the info in this thread as well.

First, what cooler options have been used and do we expect that any of them would be sufficient if the stock cooler was bypassed?

Options I have seen in this thread include:
1. Derale 13503/33503 Plate and Fin
2. Derale 13750 with elect fan (good for low speed towing or if not mounting in front)
3. CXRacing OC-KIT-CANYON28D-STOCK or BIG (assuming capacity similar, just sized diff)

@DieselDrax is your stacked plate cooler item 1 or something else?

I see a mix of 6 and 8AN sizes. I assume 6AN would be sufficient since the stock lines are 3/8"?

Early in this post, a benefit (maybe the only one) of the stock setup was heating the trans fluid with engine coolant. I wonder how this compares to the thermostat that mounts directly to the transmission (would the trans fluid heat faster internally without help of coolant?).

The thought of bypassing the stock cooler was brought up due to an alleged failure, but I only saw something about Nissan owners experiencing this. Or was I mistaken and this has happened on a 2.8?

Thanks in advance!

I think I'm the only person on these forums to have the exact issue I did with the cooling system... haven't seen many posts about issues with the diesel trans cooling system, aside from someone's buddy making an error above.

You're not losing much if you entirely bypass the stock cooler. I'm team Derale after getting a pinhole cooler from CX Racing and seeing that my experience is by far not unusual with a quick google. I'd still pressure test any brand you get, but I'd encourage you to go Derale 13750 with the fan. You can always not use the fan but if you live somewhere hot, or mountainous, or find yourself towing... would be nice to have. The thermistor makes it so it will automatically turn on, or it can be wired to be push button if you want. With a couple clever connectors, it can even be automatically turned on when enabled via push button, or manually controlled with that push button. I can make you a diagram if you need but it's nothing crazy.

Re:warmup - I don't think the coolant warms it up that fast. The IR thermostats only allow a small amount (~10% or so I think they say on the website) to circulate past the thermostat while it is closed. IE if you have the thermostat, it will allow ~10% to cycle through the lines + radiator+ aux cooler before fully opening at 165*. If you deleted the factory cooling, it would just cycle that 10% through the lines + aux cooler and return it.

You can see what the stock cooler looks like in post #8:

For ease of installation, if your stock setup is in good shape (isn't corroded, leaking, or giving you problems), I'd say you might as well include it. It's not difficult. If you ran in to an issue on the trail, it would be quite easy to bypass it with some form of coupling (whatever makes sense for your setup, could be a male to male AN6, or a barb to barb... or whatever). I always carried a few feet of 3/8" fuel line on the trail with some hose clamps and barbs... I added a couple AN6 couplers to that same bag.

 

[ARCowboy]

@ARCowboy
I put in a full aluminum radiator from a 17-22 3.6 gasser in my 19 ZR2. . The ATF tank in the bottom seemed way bigger that the stock diesel plastic tank. It took over a quart more to fill the system that previous full drains. I have the fluid flowing thru the now aluminum OEM cooler to the IR thermostat where it can bypass to the trans or go to my Long cooler @145f. I do have the PML deep pan but I had it off several times doing filters before installing the Aluminum radiator. I did the Revmax torque converter also. Part of the reason I ran thru the OEM cooler was to help warm up the trans when I was running around the oilfield in Wyoming & Utah. Also had a Duramaxtuner trans tune since 4000 miles on the truck in 19. Hottest I saw the trans was 245-250 in July 2019 towing up the long grade into Tonapaha Nevada with 115f ambient. That was with the PML pan & Trans tune but before the cooler. Only ever saw 200F after towing up the steep Cascades between Seattle & Yakima Wash. and blue mountains between Pendleton & La Grande Ore. Cabbage Hill on I84 is a real mofo that the big rig truckers despise.

Man that sounds like a great setup. And my favorite kind of mods... find something not performing to your needs, and improve it vs firing the "overland parts cannon" because tiktok influencers told you it was kewl.

That revmax TC was next on my upgrade list, looks sweet and I think Drax is running one too. The trans tune + revmax more than likely also greatly helps your trans temps with full/improved lockup, but nothing beats an aux cooler for high ambient temp, max payload/towing situations ! I'm not terribly familiar with the "Long" brand. Would you recommend it ?