2013 Z71 Suburban additional transmission cooler

[BG1988]

Just had the transmission replaced in this truck and opted to have them install an additional transmission cooler. I believe it is a “supercool” branded cooler but looking at the receipt from the work it is not specified.

Upon first driving it, after a 25-30 minute drive the trans temp was at 203; hotter than expected especially with the additional cooler. I have not tested it uphill yet. Upon inspection, the shop simply disconnected the factory fluid lines leading to the factory “cooler” within the radiator, and connected them to hoses leading to the new (and surprisingly fairly small) external cooler mounted in front of the AC condensor. They didn’t cap the old radiator input/output lines either.

From reading about external additional coolers here and other places, I was expecting this to be put in series with the factory cooler, presumably in series on the “output” side of the radiator connection. Is this not the preferred/superior solution? Or is what the transmission shop has done normal?

I’m just learning about transmission replacements and transmission coolers, so any input and recommendations here are appreciated - including superior external cooler examples if anyones has them.

Many thanks!

203F is too high mine is at 140-145f after about 75min-90min of highway driving .. pull the transmission thermostat .(thermostat delete) Why enjoy 80-100k miles of use when it can last forever...300,000 miles or 500,000 miles, a million miles?

depending on how hot it is the MAX i have seen is 165F that was when it was 110f outside most likely if it was 110f I had the a/c on MAX

the transmission thermostat is just a scam to shorten the life span of the transmission....


Just a side note: lowering the operating temp isn't a substitute for maintenance i.e changing your transmission fluid

 

[strutaeng]

Yes, leave the radiator cooler connected. There are some vehicles that it's a common failure for the radiator cooler to fail (some earlier 4Runners and Tacoma's come to mind...)but not on these trucks. Of course, just about anything fail at some point. The thermodynamics are superior fluid-to-fluid than fluid-to-air.

My brother did have a transmission failure of his 90 C1500 due to radiator cooler sending coolant into the transmission. So he bypassed it.

 

[NickTransmissions]

203F is too high mine is at 140-145f after about 75min-90min of highway driving .. pull the transmission thermostat .(thermostat delete) Why enjoy 80-100k miles of use when it can last forever...300,000 miles or 500,000 miles, a million miles?

depending on how hot it is the MAX i have seen is 165F that was when it was 110f outside most likely if it was 110f I had the a/c on MAX

the transmission thermostat is just a scam to shorten the life span of the transmission....


Just a side note: lowering the operating temp isn't a substitute for maintenance i.e changing your transmission fluid

Trucks/SUVs 2014 model year and back didn't have the cooler bypass valve installed...The CBV didn't appear until 2015+

Trans temps should be consistently 175-180 and that assumes Dex 3 or 6 (at least IMO)...Dex 6 full syn gives you more of a safety margin owing to its more robust formulation but folks sometimes push it (temps in excess of 230 frequently) and that will shorten the life of any transmission.

 

[Doubeleive]

Working with the shop now to put them in series as everyone has outlined (and how I thought it would originally be done), and we have a snag: They have said (and showed me) that the inlet connector on the 2013 SUburban radiator isn't the same type fitting we got ind n the cooler kit or that I've seen referenced in videos and posts here. Mine looks like "quick-connect" with a snap ring? The typical connectors I've seen people using (LIke the Derale part D13004, https://www.etrailer.com/Accessories-and-Parts/Derale/D13004.html ) are threaded and different from what it appears I have here?

Is anyone familiar with the actual connector I'd need to purchase so I don't need to cut the metal fluid line?

you need 2 of each of these to make it nice and not a hack-job
upper 2 are on amazon, lower 2 are on ebay
these parts work with the factory lines and tru-cool and allows you use the oem cooler in the radiator + a tru-cool

 

[j91z28d1]

Trucks/SUVs 2014 model year and back didn't have the cooler bypass valve installed...The CBV didn't appear until 2015+

Trans temps should be consistently 175-180 and that assumes Dex 3 or 6 (at least IMO)...Dex 6 full syn gives you more of a safety margin owing to its more robust formulation but folks sometimes push it (temps in excess of 230 frequently) and that will shorten the life of any transmission.

I don't really know what he's going on about but he's got a hybrid and these are kinda weird. so what I've read the electric motors can create a lot of heat but there's no torque converter to build heat. so it seems they cooled the crap out of the fluid. there's 5/8in hard lines from the tranny to a front mount cooler, that about an inch thick. (and of course discontinued) it's the size the of the rad, half is tranny, half is hybrid inverter cooling.

they seem to have a temp stat of some kind at 167*. because that's the highest anyone ever sees. takes like 2h of stop and go traffic to get there. on my the daily loop, this one only sees about 140deg on a 100 plus deg day. I've seen it hit 167 when towing a car trailer, and very very long drives. but that's about it. they also have 3 speed cooling fans, where normal is 2. I don't know if the motors are more powerful, or if they just thought having a med speed saved fuel?

so again, these are just odd ball trucks. but they definitely run colder than what is considered normal for every tranny. in all the threads I've searched about these trucks, can't say I've found anyone say they have seen the 200deg that's normal for everything else. why that is? I don't know, but besides the tranny motors it's just clutch packs. seems they could have set the stat temp at anything they wanted. it has honestly made me me wonder if over cooling tranny fluid is a real world issue or just internet theory. gm definitely didn't care that these trucks can be driven around for their whole life and never see 180deg.

 

[NickTransmissions]

I don't really know what he's going on about but he's got a hybrid and these are kinda weird. so what I've read the electric motors can create a lot of heat but there's no torque converter to build heat. so it seems they cooled the crap out of the fluid. there's 5/8in hard lines from the tranny to a front mount cooler, that about an inch thick. (and of course discontinued) it's the size the of the rad, half is tranny, half is hybrid inverter cooling.

they seem to have a temp stat of some kind at 167*. because that's the highest anyone ever sees. takes like 2h of stop and go traffic to get there. on my the daily loop, this one only sees about 140deg on a 100 plus deg day. I've seen it hit 167 when towing a car trailer, and very very long drives. but that's about it. they also have 3 speed cooling fans, where normal is 2. I don't know if the motors are more powerful, or if they just thought having a med speed saved fuel?

so again, these are just odd ball trucks. but they definitely run colder than what is considered normal for every tranny. in all the threads I've searched about these trucks, can't say I've found anyone say they have seen the 200deg that's normal for everything else. why that is? I don't know, but besides the tranny motors it's just clutch packs. seems they could have set the stat temp at anything they wanted. it has honestly made me me wonder if over cooling tranny fluid is a real world issue or just internet theory. gm definitely didn't care that these trucks can be driven around for their whole life and never see 180deg.

Are you referring to the OP?

 

[j91z28d1]

Are you referring to the OP?

nah, the BG1988 guys you quoted.

 

[NickTransmissions]

nah, the BG1988 guys you quoted.

ok - I responded to his post as he quoted the OP, telling him to pull the trans thermostat...The OP has a '13 Z71 Burban conventional gasser w/a 6L80 so wanted to let him know (just as i recently learned on this forum) that the conventional GMT900s didn't come w/the CBVs...

That out of the way, I keep thinking about your offer to send me that 2ML70 Hybrid trans...Been wanting to do one but no yard or core supplier around here has seen one in ages, lol...Perhaps we can talk off line if you get to the point you're seriously thinking about sending one to me to overhaul.

 

[j91z28d1]

ok - I responded to his post as he quoted the OP, telling him to pull the trans thermostat...The OP has a '13 Z71 Burban conventional gasser w/a 6L80 so wanted to let him know (just as i recently learned on this forum) that the conventional GMT900s didn't come w/the CBVs...

That out of the way, I keep thinking about your offer to send me that 2ML70 Hybrid trans...Been wanting to do one but no yard or core supplier around here has seen one in ages, lol...Perhaps we can talk off line if you get to the point you're seriously thinking about sending one to me to overhaul.

I'll pm you in a few.

 

[swathdiver]

Working with the shop now to put them in series as everyone has outlined (and how I thought it would originally be done), and we have a snag: They have said (and showed me) that the inlet connector on the 2013 SUburban radiator isn't the same type fitting we got ind n the cooler kit or that I've seen referenced in videos and posts here. Mine looks like "quick-connect" with a snap ring? The typical connectors I've seen people using (LIke the Derale part D13004, https://www.etrailer.com/Accessories-and-Parts/Derale/D13004.html ) are threaded and different from what it appears I have here?

Is anyone familiar with the actual connector I'd need to purchase so I don't need to cut the metal fluid line?

That's an old style connector, GM hasn't used those in over a decade. I was trying to get Derale to make us a slightly larger cooler with the OE fittings but it fell on deaf ears.

So factory installation it is for me, works fine anyways.