ADDING TRANS COOLER TO 2012 5.3 6L80

[snowboardman2002us]

So I am buying a trailer and the transmission is only cooled by the lines going into the radiator. Without towing, the transmission gets up to 220 on a hot day. I swapped the fluid and filter and now adding a cooler.

I got the tru cool 40x cooler low pressure drop, and the oil cooler manifold that had AN fittings leaving the transmission to go to the cooler.

Heres the question.

Is there a big difference in using an8 lines or an6 lines? i got an8 lines, but now i'm questioning if the pump in the trans can push that much more fluid while still maintaining good pressure..

also I've read that the 6l80 wants higher temps to run. whats too cold? I'm hoping that the transmission doesn't run too cold and now i'm creating other problems.

 

[thompsoj22]

I have the factory trans cooler and still i will upgrade to the tru cool 40k, i just havent done so yet. are you still planning on keeping the radiator in the circuit? The heat exchanger in the radiator will keep your fluid at an acceptable temp for sure, but if you are planning on deleteing the radiator circuit and plumbing from the trans to the tru cool you may have an issue in the winter? Im guessing but i doubt that the line diameter for the trans cooler lines determines the amount of flow, it is probably determined by the internal oil port that feeds the line? I have read somewhere that optimum trans temp is 160f, if you can keep the trans at or near that temp with a in line thermostat that would be an option for the peice of mind.
What type of trailer will you be towing and how heavy?

 

[SnowDrifter]

Can't comment on appropriate temps for the 6 speed. My 4l60 honestly feels the best around 130, so take that for what it's worth.

Regarding regulation; you can get oil thermostats at a couple different temps ranging from 140f to 212.

The stock lines are 3/8, or 0.375". -6AN lines are 0.355" inner diameter, which would be an appropriate match. There's not a tremendous flow rate through these coolers. Only a couple gallons per minute if memory serves. Visual estimate by watching the cooler line flushing folks is a hair over 1gpm at idle.

 

[snowboardman2002us]

I have the factory trans cooler and still i will upgrade to the tru cool 40k, i just havent done so yet. are you still planning on keeping the radiator in the circuit? The heat exchanger in the radiator will keep your fluid at an acceptable temp for sure, but if you are planning on deleteing the radiator circuit and plumbing from the trans to the tru cool you may have an issue in the winter? Im guessing but i doubt that the line diameter for the trans cooler lines determines the amount of flow, it is probably determined by the internal oil port that feeds the line? I have read somewhere that optimum trans temp is 160f, if you can keep the trans at or near that temp with a in line thermostat that would be an option for the peice of mind.
What type of trailer will you be towing and how heavy?

I removed the lines to the radiator and ran an8 lines from the transmission straight to the cooler. Well straight to where the cooler is going. Cooler should show up in the mail tomorrow. The 90 degree an fitting barely fit with the manifold adapter to the transmission. Its like 3/16" away from the front driveshaft. I figure the driveshaft and transmission wont move closer to each other. I might need a different adapter or shallow an fittings (if there is such a thing).

 

[gooffeyguy]

It will be more effective If you run it through the factory trans cooler in the radiator then through the external cooler.

The radiator cooler actually cools it. Many think the coolant in the radiator is at engine temp, but it's not, it's cooler going into the motor and picks up heat as it runs through it then gets cooled back down in the radiator

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

 

[BG1988]

So I am buying a trailer and the transmission is only cooled by the lines going into the radiator. Without towing, the transmission gets up to 220 on a hot day. I swapped the fluid and filter and now adding a cooler.

I got the tru cool 40x cooler low pressure drop, and the oil cooler manifold that had AN fittings leaving the transmission to go to the cooler.

Heres the question.

Is there a big difference in using an8 lines or an6 lines? i got an8 lines, but now i'm questioning if the pump in the trans can push that much more fluid while still maintaining good pressure..

also I've read that the 6l80 wants higher temps to run. whats too cold? I'm hoping that the transmission doesn't run too cold and now i'm creating other problems.

i have a factory cooler it runs 167F (with temperature being 100-110 ambient temp)in the summer and 155 in the winter(might be lower though) i'm not 100% sure...

 

[SnowDrifter]

It will be more effective If you run it through the factory trans cooler in the radiator then through the external cooler.

The radiator cooler actually cools it. Many think the coolant in the radiator is at engine temp, but it's not, it's cooler going into the motor and picks up heat as it runs through it then gets cooled back down in the radiator

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

Also depends on vehicle speed and fan activation. When my thermostat opens and vehicle is stopped with rad fans off, trans temp goes up. Could test if I had some access to thermal probes but I don't :/

 

[snowboardman2002us]

I dont have a thermostat on my transmission. Just comes straight out. I got the LSX innovations manifold adapter. Only problem now is that the fitting is only like 3/16 from the transmission. I'm getting a 90 npt thread to an8 so that it will fit better.

I'll add pics when i'm done