[DieselDrax]

Would you happen to have the part numbers of the 90 degree fittings from the thermostat on the transmission?

I ordered them as part of the thermostat "kit" but here's the page for just the elbow.

RaceFlux Low-Profile 90-degree -6AN Male Flare to -6AN Male O-Ring Fitting

RaceFlux Low-Profile 90-degree -6ANAN Male Flare to -6AN Male O-ring Boss Adapter

www.improvedracing.com

 

[Coloradoincolorado]

I ordered them as part of the thermostat "kit" but here's the page for just the elbow.

RaceFlux Low-Profile 90-degree -6AN Male Flare to -6AN Male O-Ring Fitting

RaceFlux Low-Profile 90-degree -6ANAN Male Flare to -6AN Male O-ring Boss Adapter

www.improvedracing.com

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

 

[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 !

 

[Coloradoincolorado]

What have your transmission temps been from this install? Towing vs normal driving?

 

[DieselDrax]

What have your transmission temps been from this install? Towing vs normal driving?

For me, I have 3 different stages and different temps as a result.

Stock cooler: Towing up grades or going slow off-road would see trans temps of 220-240F, empty temps would run up to 180-195F or so, mainly 100F over ambient.

Aux cooler downstream from OEM cooler: Trans temps were usually 50F over ambient when empty and when towing never over 200F even if I tried (towing off-road in 4L at high elevation and 20MPH or less would hit 199F).

Aux cooler, OEM cooler no longer in the loop, 160F trans thermostat in place: On the freeway it'll creep up to 145-147F, in the city and such it'll get up to 165-170F but no higher, and then when back on the freeway it'll drop back down to the 140s. Haven't towed since the t-stat install but I'm not expecting any differences to peak temps.

 

[Coloradoincolorado]

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.

 

[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.

 

[Ryanbosd]

@ARCowboy
I did a similar setup but used the 145 deg thermostat. I also put in an aluminum radiator out of a 3.6 Colorado & the CX racing intercooler. Hot line goes to Stock ATF tank in the radiator then discharge from the ATF radiator goes to the IR thermostat to bypass or go to the cooler @ 145 f.
Takes -10 ORB to -8 JIC fittings to make the -8AN lines talk to the ATF tanks in the Aluminum 3.6 Radiator. I forget the fittings the stock plastic tank took (possibly 9/16x18 to -8).
I removed all the plastic in front of the radiator & intercooler. Then welded 2 1.5”x1/8” flats in to mount too.
I had the Truecool 40k btu cooler but it broke so I put in a steel one from Long out of Canada. Ignore the paint will get it cleaned up better is on the way to the dealer tomorrow to get the balance rates set for the new engine. I had cured the horrid trans shudder using Triax Global Synthetic ATF but eventually put a Revmax TC in and the PML pan.
The thing was hitting 235-250 in the first summer I had it when towing. Now runs at 145 in the winter and 165 in the summer. Haven’t towed in a while since I got a bigger truck but highest I saw it with the PML pan and cooler was 200f towing thru the cascades and Rockies and stayed 160-170 just cruising.

 

[DieselDrax]

Ok, so tonight was the first time driving in cold weather since installing the trans t-stat and taking the stock cooler out of the loop. Basically drove 20 minutes on country roads at 60MPH for 90% of the drive, got fuel, parked for about 15 mins, drove back. Temp was 19F outside, truck parked in the garage and probably in the 50s in there. Anyway, after the first 20-minute drive the trans temp got up to 120F and then after the 20-minute drive back the trans temp was up to 154F as I pulled into the garage. Very light engine/trans load on this drive so not surprised at the slowness that the temp rose.

Anyway, huge improvement over stock + aux cooler without the t-stat, in temps like this my trans fluid would never break 100F even on the freeway at 70MPH and the increased wind resistance to put more load on the trans.

 

[CowboyBobby76]

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.

 

[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).

 

[CowboyBobby76]

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).

View attachment 482111

That makes totally sense. I’m a little worried about water crossing also, but hopefully I put the heat shrink on properly. I think I’ve seen you mention those other products before. I have several relays all under my hood. The switch panel would be a great addition.

thanks for the add a fuse and what fuse the plug it into. The add a fuse I got isn’t long enough. I really appreciate the help!

 

[ColCanfan]

I’m one of those who got bit,(badly),by a failed stock cooler. Not the fault of the part but inept shop tech. The design of the system leaves room for such mistakes in my opinion.
I may have to add an aux cooler to my rebuilt trans. It runs hotter than prior to wrecking it with engine coolant. The shop that did the rebuild,( who I really like), had to program the trans brain twice. The owner of the shop is comfortable with trans temps 120* over ambient. He does GM trans 5 days a week. Lots of 8 spds.

 

[DieselDrax]

I’m one of those who got bit,(badly),by a failed stock cooler. Not the fault of the part but inept shop tech. The design of the system leaves room for such mistakes in my opinion.
I may have to add an aux cooler to my rebuilt trans. It runs hotter than prior to wrecking it with engine coolant. The shop that did the rebuild,( who I really like), had to program the trans brain twice. The owner of the shop is comfortable with trans temps 120* over ambient. He does GM trans 5 days a week. Lots of 8 spds.

Hmm, not sure how the cooler could fail and be the fault of a shop. Can you provide more details on that?

 

[ColCanfan]

https://www.coloradofans.com/threads/6l50-saga.445691/

here is the thread from last summer

basically my friend did not know how to remove jiffytite connections and wrecked the seal/ integrity of the cooler

 

[DieselDrax]

https://www.coloradofans.com/threads/6l50-saga.445691/

here is the thread from last summer

Ah, I remember that. So not a cooler failure but improper repair. Oof.

With my stock cooler it usually ran about 80F over ambient and when towing a fair amount it was 100-120F over ambient. What actual trans fluid temps are you seeing? Around town it wasn't hard for me to get up around 200F and when towing 215-220F was the norm. If you're seeing temps over 200F when empty and just cruising then something is definitely wonky, but if it's still staying under 200F then I wouldn't be too worried, especially during the winter. My winter trans fluid temps were still getting up around 160F when it was near freezing outside and running the stock cooler.

 

[ColCanfan]

I’m in western Ma. so daytime temps now can be teens to 40s. I’m seeing 100-125 over ambient but the trans temp is not over 160 +\-
The test will be when it’s 85 and I’m towing my car. The car /trailer combo is 5700 lbs and the trip I normally take with it has some grades. 212 used to be the high trans temp in such scenarios. I’m afraid that won’t be the case going forward.

Great thread here about the cooler options!

 

[gdneely72]

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!

 

[DieselDrax]

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'm running the CX Racing cooler for the stock intercooler. The "BIG" cooler kit of theirs is referring to trucks that also have the CX Racing intercooler installed as well (the "BIG" trans cooler mounts low in the front), the surface area is likely close to the same for both (stock is shorter but wider, big is narrower and taller).

The stock trans cooler doesn't make a noticeable difference in trans temps when using an aux cooler downstream, I ran trans -> stock cooler -> aux cooler -> trans for a couple of years and my trans fluid was being overcooled in the winter which meant it wasn't getting hot enough to allow condensation to evaporate which leads to contaminated trans fluid. For the original install I was using the OEM hard line to the stock cooler and return from the aux cooler, for my current setup I removed the OEM hard lines and am running 6AN hoses to the 8AN hoses that came with the CX Racing kit, no problem there. I'm also running the Improved Racing 160F transmission t-stat to avoid overcooling.

The only OEM cooler "failure" I've heard of was not a cooler failure but bad workmanship when someone messed with the quick connect fittings, they removed or loosened them and when reinstalled they allowed coolant to contaminate the trans fluid. I bypassed the OEM cooler to avoid any potential failures or issues that might happen and to simplify my trans cooling setup.

 

[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.