Updated Thermal Control Valve

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GranPrix

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Drove around town twice today in 92 degree temps and hit 162 and 144. If that's the highest it gets I'm good otherwise I'll probably get a trucool.
 

Mr. 960

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As mentioned you can't take everything out. Doing this will trap air in the lines and the fluid will find the path of least resistance and flow right back into the trans bypassing the cooler. Also - you need to take note of where the half moon shape is on top of the cover. It is imperative that it goes back in the correct clocked position. It has passages in the body and if not put back properly it will impede or block flow to the cooler lines.
 

Sparksalot

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As mentioned you can't take everything out. Doing this will trap air in the lines and the fluid will find the path of least resistance and flow right back into the trans bypassing the cooler. Also - you need to take note of where the half moon shape is on top of the cover. It is imperative that it goes back in the correct clocked position. It has passages in the body and if not put back properly it will impede or block flow to the cooler lines.
I did not see any mention of the clocking in the videos I watched about it.
 

RLC2020

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A few things after having the pill flipped for a few months now. Temps are great, usually around 140 empty, up to 175 or so light towing. Much better than the near 200 it was at before. Also, even though I have a 2015 model, my lines were the newer style, not the older style. Just something to think about if you plan to order the new housing, look under the truck first and see what style you have, not all 2015's were the old style apparently.

I was planning to order the new tsat housing but after the pill flip I'm satisfied with how it runs. Trans shifts great, switching the fluid to Amsoil may have helped too.
It is imperative that it goes back in the correct clocked position. It has passages in the body and if not put back properly it will impede or block flow to the cooler lines.
I guess I got lucky, I did not pay attention to the position of the cap when I put mine back together.
 

Tonyv__

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A few things after having the pill flipped for a few months now. Temps are great, usually around 140 empty, up to 175 or so light towing. Much better than the near 200 it was at before. Also, even though I have a 2015 model, my lines were the newer style, not the older style. Just something to think about if you plan to order the new housing, look under the truck first and see what style you have, not all 2015's were the old style apparently.

I was planning to order the new tsat housing but after the pill flip I'm satisfied with how it runs. Trans shifts great, switching the fluid to Amsoil may have helped too.

I guess I got lucky, I did not pay attention to the position of the cap when I put mine back together.

I’m considering doing this to my 2015 Yukon…. One thing I haven’t seen in any of the videos, do I need to replace any gaskets? Like is there a gasket from the thermostat block to the transmission that I’ll need to replace?
 

Prospect62

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I’m considering doing this to my 2015 Yukon…. One thing I haven’t seen in any of the videos, do I need to replace any gaskets? Like is there a gasket from the thermostat block to the transmission that I’ll need to replace?
This mod (at least doing it this way with GM parts) is only applicable to the 2016 and newer trucks. The 2015 and older trucks use a different quick release type fitting on the cooler lines that aren't compatible with the updated TBV part #86774933 (thermal bypass valve).

There are still DIY or aftermarket ways you can accomplish the same thing. This, for example, will do the same thing and should work with your 2015...


The lines themselves don't have a seal on your application. On the newer trucks they have an o-ring (but these don't really need to be replaced anyway). There is, however, a gasket that goes between the thermostat and the transmission body:


But that seldom has to be replaced either. You could do it as cheap insurance, and I would.
 

Tonyv__

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This mod (at least doing it this way with GM parts) is only applicable to the 2016 and newer trucks. The 2015 and older trucks use a different quick release type fitting on the cooler lines that aren't compatible with the updated TBV part #86774933 (thermal bypass valve).

There are still DIY or aftermarket ways you can accomplish the same thing. This, for example, will do the same thing and should work with your 2015...


The lines themselves don't have a seal on your application. On the newer trucks they have an o-ring (but these don't really need to be replaced anyway). There is, however, a gasket that goes between the thermostat and the transmission body:


But that seldom has to be replaced either. You could do it as cheap insurance, and I would.
Thank you for the detailed response
 

Rygrego

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Just installed the updated TCV (thermostat) for my 6L80e. Took about 30 min once I found the correct size sockets and got set up. Trans temp now doesn’t go about 150. Part was about 50 bucks. Part number is 86774933 if anyone is interested. I think it’s well worth it.
Been there, done that. I think you'll find it was a good move.
 

tom3

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Anyone have any luck actually ordering the trans. temp. control valve lately? I've been all over the net trying to order this and just keep going around in circles. GMpartsdirect's cart only offers a quote via email, then goes back to the order page, click to get email quote again, no way to actually order. Other companies' pages either say invalid VIN or just goes to a blank page. Anyone got any help on this? I do see an aftermarket kit on Amazon to convert my OE valve to the lower temp but I'd sure rather use GM parts on this newer machine.
 
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