2017 6l80 operating temps

[Cody Shandley]

2017 1500 SLT, 52kmiles, stock other than GM/Borla.  Truck is never used for towing, but is my daily driver. I noticed recently there is an "odd" upshift between 2nd and 3rd at random times.  Usually after driving for a while. Took it in to the dealer who says all is good, no burned fluid and can't duplicate the issue--they say they took it up to ~190.  I drove the truck about 470 miles this weekend on vacation after dealer cleared it, but monitored the tranny temps more closely and noticed on the long highway drive with minimal cargo/passengers temp is sitting around 225-232. Ambient temps in the upper 90's. 

 

This seems high to me with very little load, but I never really paid attention to temps prior to the shifting issue... so no baseline to compare to. What temps are expected/normal?  

 

 

[Black02Silverado]

That  is high considering most only get to 200 or less.  Do you have 8sp or 6sp?  The 6sp has a new thermostat from GM that you can get and put on that will lower the temp.

[Cody Shandley]

Thanks for the reply. It has the 6-speed.  Do you by chance know the thermostat part number or what to ask for at the dealer?  They acted as if I was an idiot before... 

[Black02Silverado]

Sorry but just realized you posted in the title 6L80.  Duh!!!!  Here is the TSB

 

 

[Cody Shandley]

5 minutes ago, Black02Silverado said:

Sorry but just realized you posted in the title 6L80.  Duh!!!!  Here is the TSB

 

 

Thanks!!!

[Spurshot]

 

48 minutes ago, Cody Shandley said:

Thanks for the reply. It has the 6-speed.  Do you by chance know the thermostat part number or what to ask for at the dealer?  They acted as if I was an idiot before... 

 

You can go that route, which gives you a valve that supposedly operates at a minimum of 158F, but people are still seeing light load operating temps well above that. 

 

People that are doing either an aftermarket thermal bypass valve disable kit,  Superior STL010 | Superior Transmission Parts - The problem solvers of the transmission industry

 

...Or by just disassembling the OEM valve and changing the orientation of a couple parts inside. 

6l80 bypass pill flip - Google Search   are seeing very low temperatures.  

Edited June 29, 2022 by Spurshot

[Cody Shandley]

1 hour ago, Spurshot said:

 

 

You can go that route, which gives you a valve that supposedly operates at a minimum of 158F, but people are still seeing light load operating temps well above that. 

 

People that are doing either an aftermarket thermal bypass valve disable kit,  Superior STL010 | Superior Transmission Parts - The problem solvers of the transmission industry

 

...Or by just disassembling the OEM valve and changing the orientation of a couple parts inside. 

6l80 bypass pill flip - Google Search   are seeing very low temperatures.  

Thank you 

[Spurshot]

19 hours ago, Cody Shandley said:

Thank you 

If you watch that video, he points out that the new thermal bypass valve fits with only the newer cooler line connectors.  I don't recall when the changeover to the new style lines was implemented.   Easiest thing to do is to slide under the truck and look at what you have compared to what's shown in the video.  The older style lines have individual wire retainers and the new style lines have a flat plate that has slots for two lines and a bolt in the middle. 

 

 

Edited June 30, 2022 by Spurshot

[steelerdude15]

On 6/29/2022 at 2:56 PM, Spurshot said:

 

 

You can go that route, which gives you a valve that supposedly operates at a minimum of 158F, but people are still seeing light load operating temps well above that. 

 

People that are doing either an aftermarket thermal bypass valve disable kit,  Superior STL010 | Superior Transmission Parts - The problem solvers of the transmission industry

 

...Or by just disassembling the OEM valve and changing the orientation of a couple parts inside. 

6l80 bypass pill flip - Google Search   are seeing very low temperatures.  

This is what I did to help keep my transmission cooler. Its free and pretty easy to do. I'd also check your fluid and make sure its in good condition after getting that hot.

Edited June 30, 2022 by steelerdude15