What Is The Thread Size of The Trans Cooler Fittings In The Radiator?

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Scrappycrow

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Y'all,

I am planning an installation of a remote spin-on filter, thermostat, and auxiliary cooler on my '13 LTZ. As of now, my intent is to use the stock hard lines from the transmission up to the point they pass the harmonic balancer, a couple of short sections of soft line, and then 3/8 nickel-copper (AKA nicopp, cunifer) and AN-6 fittings throughout the rest. While I can use the ends of the stock lines where they enter the radiator, I would prefer to be able to use an adapter that can replace the stock quick-connect fittings with a fitting that has a male AN-6 connection. I am aware of adapters like this Derale 13035, but I do not want to use these because I want to minimize the total amount of soft line and hose clamps and want to be able to make a 90° bend as close to the radiator as possible (whether via an AN-6 elbow or a bend in a hard line).

So, what is the thread size of the male side of the quick-connect fittings that screw into the radiator? While I can pull one to measure, I'd prefer not to because I don't have one of those clip tools and I don't have a replacement o-ring on hand (and can't readily find the P/N for it).

Before anyone asks about the thermostat, the way I will be plumbing it, the stock in-radiator cooler will always be in the loop and the auxiliary cooler will only brought in downstream once the thermostat directs the fluid to it. Yes, I am aware this is not how any stock arrangement is, and I am aware that few people plumb auxiliary coolers like this. Yes, I live in Georgia, but I also regularly take trips to Minnesota in the depths of winter, and I want the fluid to come up to temperature as quickly as possible in whatever weather. Companies like Derale and Perma-Cool do not make these thermostats because people don't use them, you know. ;)

TL;DR What is the thread size of the male side of the quick-connect trans cooler fittings in the radiator?

Thanks,
Scrappy
 

mikez71

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Is the female side a different thread size? :p

outside diameter of threads looked like 14mm with a ruler..

but dorman part says 5/8-18...
 
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mikez71

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Ah, gotcha. Calipers measured 14.15mm..
thread pitch looks like 1.5mm..
IMG_1130.jpeg


BUT that is a 2005 GM radiator.. Which uses the same generic replacement radiator as my 2012.
 
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mikez71

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Thank you for making the effort to measure for me!
No problem!

Unfortunately it looks like I measured the wrong year.. It seems like the older transmissions used a different size..

Glad you didn't go off my measurements!
 

Fless

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Interesting that those are SAE threads.

When I worked at Caterpillar winding hydraulic hose, our (old) line winding machines were a mix of metric and SAE fasteners and parts. One never knew what tool would be needed.
 
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Doubeleive

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Y'all,

I am planning an installation of a remote spin-on filter, thermostat, and auxiliary cooler on my '13 LTZ. As of now, my intent is to use the stock hard lines from the transmission up to the point they pass the harmonic balancer, a couple of short sections of soft line, and then 3/8 nickel-copper (AKA nicopp, cunifer) and AN-6 fittings throughout the rest. While I can use the ends of the stock lines where they enter the radiator, I would prefer to be able to use an adapter that can replace the stock quick-connect fittings with a fitting that has a male AN-6 connection. I am aware of adapters like this Derale 13035, but I do not want to use these because I want to minimize the total amount of soft line and hose clamps and want to be able to make a 90° bend as close to the radiator as possible (whether via an AN-6 elbow or a bend in a hard line).

So, what is the thread size of the male side of the quick-connect fittings that screw into the radiator? While I can pull one to measure, I'd prefer not to because I don't have one of those clip tools and I don't have a replacement o-ring on hand (and can't readily find the P/N for it).

Before anyone asks about the thermostat, the way I will be plumbing it, the stock in-radiator cooler will always be in the loop and the auxiliary cooler will only brought in downstream once the thermostat directs the fluid to it. Yes, I am aware this is not how any stock arrangement is, and I am aware that few people plumb auxiliary coolers like this. Yes, I live in Georgia, but I also regularly take trips to Minnesota in the depths of winter, and I want the fluid to come up to temperature as quickly as possible in whatever weather. Companies like Derale and Perma-Cool do not make these thermostats because people don't use them, you know. ;)

TL;DR What is the thread size of the male side of the quick-connect trans cooler fittings in the radiator?

Thanks,
Scrappy



 

Doubeleive

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if you want to use the oem quick connect lines and adapt to whatever, use the oem female to male adapter I linked above otherwise you have to cut the lines
those 2 adapter types allow you to convert the oem quick connect to 6an and won't leak. you might be able to find the female 5/8-18 to 6an cheaper than $20
 
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Scrappycrow

Scrappycrow

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if you want to use the oem quick connect lines and adapt to whatever, use the oem female to male adapter I linked above otherwise you have to cut the lines
those 2 adapter types allow you to convert the oem quick connect to 6an and won't leak. you might be able to find the female 5/8-18 to 6an cheaper than $20
Thanks! The only parts I'm concerned about adapting are the female fittings in the radiator that the stock quick-connect fittings screw into.

The original hard line ends will be gone from the equation, as I'll be cutting the original hard lines near where they make the turn in front of the harmonic balancer and either flaring and using AN-6 ferrules and tube nuts, or cutting and using 3/8" compression to AN-6 fittings. I'll probably do the latter, as I can't be sure the tubing would seal well after flaring (I have no idea of the condition of the inner surface or if there are any seams). Yes, I do know about these things and have used them on problem fittings before.
 
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