Auxiliary external transmission oil cooler

[Okie72]

I just purchased a new 2018 z71 LT, and was just wondering if it came with an auxiliary external transmission oil cooler?  It has the trailering package, but not the Max package.

Any help on this would be greatly appreciated.

 

Thanks!

[L86 All Terrain]

I am not 100% on this but I believe that you have to get NHT to get a factory auxiliary cooler, they may come stock in LTZ and SLT trim levels with towing package? The integrated trans cooler is designed to maintain trans temps. at normal, in and around your gross vehicle weight rating. I have towed quite a few different items with my little WT 6L80e 5.3L and the trans has never went higher than 94 degree Celsius (201.2 F). Of course, in the mountains this can change. In my opinion, if you need more cooling because your trans is overheating you need at least an NHT or 3/4ton, preferably the latter.  

[diyer2]

Pulling the grades to get to our house in the mountains, in the summer I see 201 degree trans temps with an empty truck.

I was surprised the first time I checked the trans temp after parking in the garage.

I have factory oil and trans fluid external coolers.

 

[KurtA]

My '17 Silverado with the 5.3 ltr engine has the radiator tank cooler along the side. There's also another cooler above the condenser with the lines running back along the passenger side of the engine.   Is this an oil cooler, or an auxiliary transmission cooler? 

[15slvrDbl]

All the 5.3 and 6.2’s get the ext cooler on top of the condenser that I have seen the 4.3’s do not. Same as the last model chevy’s the 4.8 didn’t get the ext cooler but the 5.3 and 6.0, 6.2’s did. 

[truckguy82]

On 3/19/2018 at 3:52 PM, diyer2 said:

Pulling the grades to get to our house in the mountains, in the summer I see 201 degree trans temps with an empty truck.

I was surprised the first time I checked the trans temp after parking in the garage.

I have factory oil and trans fluid external coolers.

 

Thats because we have a trans thermostat.

 

the transmission oil does not start flowing to the trans cooler until 190 degrees.

 

Doesn’t matter if it’s winter or summer or your pulling weight or empty, your trans temp is goin to be between 190 and 205. (Unless you’re pulling serious weight)

 

our factory trans cooling system is fantastic, it just intentionally keeps the temps around 200 degrees.

[diyer2]

truckguy82

I thought the newer trucks had the trans thermostat, not my 2012.

 

[Doublebase]

On 5/30/2018 at 7:40 AM, truckguy82 said:

Thats because we have a trans thermostat.

 

the transmission oil does not start flowing to the trans cooler until 190 degrees.

 

Doesn’t matter if it’s winter or summer or your pulling weight or empty, your trans temp is goin to be between 190 and 205. (Unless you’re pulling serious weight)

 

our factory trans cooling system is fantastic, it just intentionally keeps the temps around 200 degrees.

Yeah most trucks are doing this now, ive noticed because when you go to do a transmission flush you're not getting any fluid flowing to the cooler until you bypass that thermostat. Reaching operating temperature fast, and keeping it there is very important to the life of these transmissions. 

[Jon A]

On 5/30/2018 at 4:58 AM, diyer2 said:

I thought the newer trucks had the trans thermostat, not my 2012.

Yes, I believe you're correct.  Since this is the 2014+ section, I think everybody assumes posts will be about 2014+ trucks.

 

On 3/19/2018 at 10:01 AM, Okie72 said:

Any help on this would be greatly appreciated.

While it's not as obvious as it is on trucks with a separate cooler, you can easily see it from the front if you know what to look for.  If you shine a light into your grill and look closely at the A/C condenser,  you can see the plates (between the fins) for the top 8-9 rows of the condenser are noticeably thicker.  That's the external trans cooler.

[Grumpy Bear]

7 hours ago, Doublebase said:

Yeah most trucks are doing this now, ive noticed because when you go to do a transmission flush you're not getting any fluid flowing to the cooler until you bypass that thermostat. Reaching operating temperature fast, and keeping it there is very important to the life of these transmissions. 

This is something I've kept a close eye on for two seasons. I haven't found this to be true. Tis, in part, the reason I bypassed the thermostat all together. If rapid heat to 192 F was their goal they failed in Northern Illinois winters where I routinely observed a distance of 100 miles or more and in excess of 2 hours to reach that temperature. In my normal day to day and again during winter it never exceeded 125 F. In the heat of summer I saw temperatures routinely over 210 F  and it still took roughly 50 miles or a bit over an hour to reach it. With the Thermostat bypassed I'm between 135/150 F winter 145/160 F summer in about 20 miles or 30 minutes.  GM missed the part that the transmission fluid during warm up is colder than the radiator fluid and the radiator fluid is colder than the transmission fluid after that point. So it's a heater until it's a cooler    and it does both quicker than friction does in as designed situations.

 

Disclaimer. I have the V6 layout. It would be a different with the air exchanger that is fitted to the V8 models. Jon A is working that system up and more familiar with it than I so restrict your reference of my experiences to the 15 and later V6 models that are air exchange delete. 

 

[Doublebase]

On 6/10/2018 at 3:50 PM, Grumpy Bear said:

This is something I've kept a close eye on for two seasons. I haven't found this to be true. Tis, in part, the reason I bypassed the thermostat all together. If rapid heat to 192 F was their goal they failed in Northern Illinois winters where I routinely observed a distance of 100 miles or more and in excess of 2 hours to reach that temperature. In my normal day to day and again during winter it never exceeded 125 F. In the heat of summer I saw temperatures routinely over 210 F  and it still took roughly 50 miles or a bit over an hour to reach it. With the Thermostat bypassed I'm between 135/150 F winter 145/160 F summer in about 20 miles or 30 minutes.  GM missed the part that the transmission fluid during warm up is colder than the radiator fluid and the radiator fluid is colder than the transmission fluid after that point. So it's a heater until it's a cooler    and it does both quicker than friction does in as designed situations.

 

Disclaimer. I have the V6 layout. It would be a different with the air exchanger that is fitted to the V8 models. Jon A is working that system up and more familiar with it than I so restrict your reference of my experiences to the 15 and later V6 models that are air exchange delete. 

 

I'll have to keep an eye on mine in the winter...haven't owned the truck long enough, but right now my tranny temp is generally between 181-191. It'll go up a few degrees sitting in traffic or climbing some big hills. 

[Jon A]

On 6/10/2018 at 12:50 PM, Grumpy Bear said:

This is something I've kept a close eye on for two seasons. I haven't found this to be true. Tis, in part, the reason I bypassed the thermostat all together. If rapid heat to 192 F was their goal they failed in Northern Illinois winters where I routinely observed a distance of 100 miles or more and in excess of 2 hours to reach that temperature. In my normal day to day and again during winter it never exceeded 125 F. In the heat of summer I saw temperatures routinely over 210 F  and it still took roughly 50 miles or a bit over an hour to reach it. With the Thermostat bypassed I'm between 135/150 F winter 145/160 F summer in about 20 miles or 30 minutes.  GM missed the part that the transmission fluid during warm up is colder than the radiator fluid and the radiator fluid is colder than the transmission fluid after that point. So it's a heater until it's a cooler    and it does both quicker than friction does in as designed situations.

 

Disclaimer. I have the V6 layout. It would be a different with the air exchanger that is fitted to the V8 models. Jon A is working that system up and more familiar with it than I so restrict your reference of my experiences to the 15 and later V6 models that are air exchange delete. 

 

That's good info.  The V8's do seem to warm up faster and run warmer in the winter (mine would always be in the 195 degree range no matter how cold it was) and that makes sense when you think about how the two systems are laid out differently.  That's probably one reason GM puts a higher temp thermostat on the V6's.

 

It's good info for those with V8's as well who may be thinking of using a lower temp thermostat but be worried about the fluid being "too cold" to know that the V6's run pretty cold in the winter even in stock form, so it's not likely to have any adverse effects on the transmission.

[Grumpy Bear]

6 hours ago, Jon A said:

That's good info.  The V8's do seem to warm up faster and run warmer in the winter (mine would always be in the 195 degree range no matter how cold it was) and that makes sense when you think about how the two systems are laid out differently.  That's probably one reason GM puts a higher temp thermostat on the V6's.

 

It's good info for those with V8's as well who may be thinking of using a lower temp thermostat but be worried about the fluid being "too cold" to know that the V6's run pretty cold in the winter even in stock form, so it's not likely to have any adverse effects on the transmission.

The V6 has a 207 F thermostat. What's in the V8?

[Jon A]

I was talking about the trans thermo.  You said yours was 192, mine was 180.  I think the reason is the hot-tank coolers acting as heaters most of the time on the V8's.

[Grumpy Bear]

10 hours ago, Jon A said:

I was talking about the trans thermo.  You said yours was 192, mine was 180.  I think the reason is the hot-tank coolers acting as heaters most of the time on the V8's.

Ah, my misunderstanding. Thanks for the correction to my thought. Appreciated greatly.