Transmission Temps High When Towing

[papageoff]

I have a '15 1500 and when I tow my camper (~7k lbs) I'm seeing the transmission hover around 190F and go as high as 205F.  This is after I did a complete flush with fresh Amsoil fluid and installed the thermostat bypass. 

The bypass works great when I'm not towing.  The temps have dropped between 20-30 degrees in normal driving.  But the radiator can't keep the fluid any cooler when I've got the added load of towing.  I'm not looking for it to be 100F all the time, I'd just like to get those towing temps down a little more. 

 

I don't have the towing package.  So there's no stock cooler other than the radiator tank and was considering this kit https://www.mishimoto.com/chevrolet-silverado-2014-1500-v8-transmission-cooler.html.  I'm just worried that now that I've taken out the thermostat, when I go up north for Christmas, I'll run into problems.

 

Any thoughts?

 

[diyer2]

Adding a cooler and changing fluid more often is the best answer. I use Amsoil products, great stuff in my opinion.

[Grumpy Bear]

10 hours ago, papageoff said:

I have a '15 1500 and when I tow my camper (~7k lbs) I'm seeing the transmission hover around 190F and go as high as 205F.  This is after I did a complete flush with fresh Amsoil fluid and installed the thermostat bypass. 

The bypass works great when I'm not towing.  The temps have dropped between 20-30 degrees in normal driving.  But the radiator can't keep the fluid any cooler when I've got the added load of towing.  I'm not looking for it to be 100F all the time, I'd just like to get those towing temps down a little more. 

 

I don't have the towing package.  So there's no stock cooler other than the radiator tank and was considering this kit https://www.mishimoto.com/chevrolet-silverado-2014-1500-v8-transmission-cooler.html.  I'm just worried that now that I've taken out the thermostat, when I go up north for Christmas, I'll run into problems.

 

Any thoughts?

 

 

It won't be a problem. If it were then most of the world above the 40th that drive less than 10 miles to work would have some real issues. They don't and you won't. I ran a flip for a few years before this new 70C stat came out and she was fine even at -25 F. 

[TheRiver]

You typed that you have a '15 V-8......................which, I believe, routes the trans cooler lines to the radiator prior to entering the "condenser/trans cooler" in front of the radiator..................just like the V-6's.

 

I have a '16;  and my trans cooler lines go directly to the "condenser/trans cooler".  When I tow heavy;  I drop her into M5 and let her spin at the higher rpms.  Engine runs cooler, and the tranny will like it much more also.  I have no qualms about running 65mph towing in M5.

[newdude]

On 7/20/2024 at 12:09 PM, papageoff said:

I have a '15 1500 and when I tow my camper (~7k lbs) I'm seeing the transmission hover around 190F and go as high as 205F.  This is after I did a complete flush with fresh Amsoil fluid and installed the thermostat bypass. 

The bypass works great when I'm not towing.  The temps have dropped between 20-30 degrees in normal driving.  But the radiator can't keep the fluid any cooler when I've got the added load of towing.  I'm not looking for it to be 100F all the time, I'd just like to get those towing temps down a little more. 

 

I don't have the towing package.  So there's no stock cooler other than the radiator tank and was considering this kit https://www.mishimoto.com/chevrolet-silverado-2014-1500-v8-transmission-cooler.html.  I'm just worried that now that I've taken out the thermostat, when I go up north for Christmas, I'll run into problems.

 

Any thoughts?

 

 

 

You do have the heavy cooling because its a V8.  Being its a 2015, your transmission cooler fluid path goes to the tranmission cooler tank in the main engine radiator first, then out to the auxiliary cooler which is a part of the AC condenser out front.

 

Here's the cooler line flow for your truck:

 

 

 

Even with the TBV bypass installed, you will still see higher temps than a later built truck like a 2017 or 2018 as those do not flow through the radiator.

 

The Mishimoto kit appears to add its cooler as a 3rd cooler inline with the factory setup.  So the out line from the condenser gets replaced with a line that will flow it to the Mishimoto, and then from the Mishimoto it will connect back to the transmission inlet line.  You will probably see a temp reduction if you install this because you have a 2014-early 2016 truck.  

 

One thing I would consider though is experimenting with the lower temp TBV that GM has if the truck runs too cold empty.  Especially if you live where it gets cold, the Mishimoto might overcool, but again, you won't know until you set it up on your truck.  

 

 

Edited July 23 by newdude

[Grumpy Bear]

5 hours ago, newdude said:

Even with the TBV bypass installed, you will still see higher temps than a later built truck like a 2017 or 2018 as those do not flow through the radiator.

 

The early trucks that use the 'hot tank' for a cooler, aren't using it as a cooler but as a heater. 207 F+ water temp on entry. 

 

If it were mine AND I the AC condenser is in play I'd bypass the radiator part of the system and run it like a 2017 +. 

 

Am I wrong? 

[customboss]

On 7/20/2024 at 10:09 AM, papageoff said:

I have a '15 1500 and when I tow my camper (~7k lbs) I'm seeing the transmission hover around 190F and go as high as 205F.  This is after I did a complete flush with fresh Amsoil fluid and installed the thermostat bypass. 

The bypass works great when I'm not towing.  The temps have dropped between 20-30 degrees in normal driving.  But the radiator can't keep the fluid any cooler when I've got the added load of towing.  I'm not looking for it to be 100F all the time, I'd just like to get those towing temps down a little more. 

 

I don't have the towing package.  So there's no stock cooler other than the radiator tank and was considering this kit https://www.mishimoto.com/chevrolet-silverado-2014-1500-v8-transmission-cooler.html.  I'm just worried that now that I've taken out the thermostat, when I go up north for Christmas, I'll run into problems.

 

Any thoughts?

 

205F for Amsoil ATF is not going to harm the fluid or the transmission. I would do nothing but make sure your running the recommended Amsoil in that the lower vis Amsoil version could cut another 20-30F under load. 

[papageoff]

20 hours ago, newdude said:

 

 

You do have the heavy cooling because its a V8.  Being its a 2015, your transmission cooler fluid path goes to the tranmission cooler tank in the main engine radiator first, then out to the auxiliary cooler which is a part of the AC condenser out front.

 

Here's the cooler line flow for your truck:

 

 

 

Even with the TBV bypass installed, you will still see higher temps than a later built truck like a 2017 or 2018 as those do not flow through the radiator.

 

The Mishimoto kit appears to add its cooler as a 3rd cooler inline with the factory setup.  So the out line from the condenser gets replaced with a line that will flow it to the Mishimoto, and then from the Mishimoto it will connect back to the transmission inlet line.  You will probably see a temp reduction if you install this because you have a 2014-early 2016 truck.  

 

One thing I would consider though is experimenting with the lower temp TBV that GM has if the truck runs too cold empty.  Especially if you live where it gets cold, the Mishimoto might overcool, but again, you won't know until you set it up on your truck.  

 

 

 

 

20 hours ago, TheRiver said:

You typed that you have a '15 V-8......................which, I believe, routes the trans cooler lines to the radiator prior to entering the "condenser/trans cooler" in front of the radiator..................just like the V-6's.

 

I have a '16;  and my trans cooler lines go directly to the "condenser/trans cooler".  When I tow heavy;  I drop her into M5 and let her spin at the higher rpms.  Engine runs cooler, and the tranny will like it much more also.  I have no qualms about running 65mph towing in M5.

 

 

I don't know how I missed that it's going through the condenser all this time, but I honestly never knew that.  That's wild.  It makes sense.  I always knew the engine coolant would warm it up when it's cold, but I just assumed the engine coolant was the only "cooler" for the transmission.   There's always something to learn.

 

14 hours ago, Grumpy Bear said:

 

The early trucks that use the 'hot tank' for a cooler, aren't using it as a cooler but as a heater. 207 F+ water temp on entry. 

 

If it were mine AND I the AC condenser is in play I'd bypass the radiator part of the system and run it like a 2017 +. 

 

Am I wrong? 

 

So originally I was considering bypassing the radiator with an aftermarket cooler.  But then I saw that kit with all the lines pre-bent and was intrigued.  That was also before I knew about the condenser being in play. 

Your thought about the newer GM part is a good one too, but I'd have to change the lines to use it I think.  Unless the innards fit in the thermostat block I already have.  I suppose I could just make new line altogether too, but I don't really have the tools for that on hand. I'll consider that.

I have a few weeks before my next tow.  I'll stew on it.  I'm not sure I wanna spend $500 on a cooler and end up needing a thermostat again.

[Black02Silverado]

You didn't say how many miles are on your truck.  So if you have not changed it out it would be a good idea to do so.  AMSOIL's ATL  low viscoity fluid is what you would use if you want to use AMSOIL.  I can get you a quote if interested. Just let me know.  The dealership here did an exchange on my truck for $139 and I provided the fluid. Some independent shops can do the same, just have to shop around if you don't want to do it yourself. 

 

The blue ATF in the picture is what you want to get, product code ATL.  You can get a capacities list from here. 

[papageoff]

On 7/25/2024 at 12:33 PM, Black02Silverado said:

You didn't say how many miles are on your truck.  So if you have not changed it out it would be a good idea to do so.  AMSOIL's ATL  low viscoity fluid is what you would use if you want to use AMSOIL.  I can get you a quote if interested. Just let me know.  The dealership here did an exchange on my truck for $139 and I provided the fluid. Some independent shops can do the same, just have to shop around if you don't want to do it yourself. 

 

The blue ATF in the picture is what you want to get, product code ATL.  You can get a capacities list from here. 

 

I have about 130k.  It's been done a couple times before.  At least once that I remember for sure, but I think a second too. 

 

Thanks for your offer, but I already changed it with amsoil before I made this post.  I did use the fluid you called out.  I'm no stranger to amsoil.  I use it in everything except the engine in all of my vehicles.  I've always been a mobil 1 guy for that.