Trans Temp always HOT

Brandin Boisclair · April 4, 2020

Hey everyone,

I’m new to the forum. To start out, I have a 2014 Silverado 1500 5.3 with 65k miles. I’m on 33x12.50 tires and factory gearing(which I believe is 3.42 or 3.24, something like that). I’ve noticed my transmission temp gets hot all the time without towing or driving like an idiot. I’m running around 194-199 driving 80 on the flat interstate with ambient temperature around 60-65°. The trans is also starting to develop a small flare between 2-3 and 3-4. My local shop said the trans is starting to fail and it didn’t have any codes. I wanted a second opinion so I took it to a reputable transmission shop in town. He told me it was the torque converter starting to fail and that I should replace it and be good to go. He said he has seen this problem before on the 6L80’s and it will fix it. I just figured I’d ask y’all before I pay $1000 to have the converter replaced. Thanks!

UnlimitedMatt · April 4, 2020

I am no expert but those temps are 'normal' for these transmissions. This is why many of us do the transmission thermostat delete mod. After I did this, my temps never get that hot anymore.

I don't have any ideas on your shifting issues. All I'd suggest is to do a full transmission fluid change.

Good luck!

flyingfool · April 4, 2020

its not normal! correct temp should be around 120-160

if your getting flair, take to dealer and have them do the recalibration on the TCM, there is also an ovehaul cleaning procedure that the GM technitian can perform which basically is a self cleaning procedure of the valvebody solenoids and and air/fluid purge of the Valve body curcuits .. after this it will drive normal again. but i would recommend driving the truck in M4, and M5 mode until its corrected

then after this , get the circle D torque converter with OEM stall speed

Edited April 4, 2020 by flyingfool

gone_fishing · April 4, 2020

194F is normal as thats the thermostat bypass setting.

flyingfool · April 4, 2020

36 minutes ago, gone_fishing said:

194F is normal as thats the thermostat bypass setting.

must have did it wrong or your drag racing

Brandin Boisclair · April 4, 2020

43 minutes ago, flyingfool said:

its not normal! correct temp should be around 120-160

if your getting flair, take to dealer and have them do the recalibration on the TCM, there is also an ovehaul cleaning procedure that the GM technitian can perform which basically is a self cleaning procedure of the valvebody solenoids and and air/fluid purge of the Valve body curcuits .. after this it will drive normal again. but i would recommend driving the truck in M4, and M5 mode until its corrected

then after this , get the circle D torque converter with OEM stall speed

My friend has a 2011 1500 and his 6L80 runs around 150-160 which seems MUCH more normal. What do I say to the dealers about me wanting all that done? I assume I have to pay for all of that as well? And what is the benefit of replacing the converter after all of that is done?

flyingfool · April 4, 2020

2014-2019 trucks got the thermostat. early trucks ran cooler trans. its all about getting you into a new model truck when parts cost is too high to repair

if your cheap, you can have a mechanic, take out the thermostat pill, turn it upside down and reinstall, I heard this also works, lots of YT vids on doing it correctly.

flyingfool · April 4, 2020

the converters are poorly made in the 8 speed trucks,

i have 6 speed and not seen any issues yet, if you have vibrations in drive line the converter is probably failing . shift flair is not torque converter related, its software tuning and the computer learning your driving style. but this is not 100% . high temps may have degraded parts in the converter and cause a failure.

gm mechanics will not modify your thermostat. deff have the gm techs do a trans recal and check the trans filter for excessive metal debris to confirm parts are ok

Edited April 4, 2020 by flyingfool

MikeNH · April 4, 2020

2014+ 1500s run around 200 degrees. This is normal no matter how much anyone says otherwise. Whether it is good or not is another matter.

Edited April 4, 2020 by MikeNH

gone_fishing · April 4, 2020

13 minutes ago, flyingfool said:

must have did it wrong or your drag racing

Just normal highway driving and up to full operating temp I usually see between 192F and 196F on my 2014 Sierra 6 speed. I think its been established this is normal for the 6-speed K2 1/2 tons (assuming you are stock and haven't modified the bypass valve).

flyingfool · April 4, 2020

operating at 200+F will dramatically shorten the usefull life of all the components inside your trans. 100-150,000 miles is all you'll get in city driving

MikeNH · April 4, 2020

4 minutes ago, flyingfool said:

operating at 200+F will dramatically shorten the usefull life of all the components inside your trans. 100-150,000 miles is all you'll get in city driving

No one is saying that 200 is good for it. Just saying it is normal for these trucks. Well aware that newer 6L80s don't have a great reputation for longevity.

CamGTP · April 4, 2020

Anything over 215-220 is where fluid life drops. Fluid life has always been just fine at 160-200 degrees.

My truck gets to 180-190 after a while of driving.

The OP should do the thermostat mod and see what happens. Your temps will drop 20-30 degrees easy.

flyingfool · April 4, 2020

190-220 degrees wasn't normal back in 2012 trucks, they ran at 130-160 normal driving conditions. it's not just the fluid life you should be worried about.. lots of the components that make these transmissions function are made of plastic and rubber. once you hit 180-220 degrees you are just oxidizing and hardening all these soft components that maintain the sealing and pressure to control of the fluids mechanicals function to do its job., overtime these soft parts will disintegrate like a set of old wiperblades trying to squeeze water off your windshield, it just aint gonna work right

truckguy82 · April 4, 2020

2 hours ago, flyingfool said:

its not normal! correct temp should be around 120-160

if your getting flair, take to dealer and have them do the recalibration on the TCM, there is also an ovehaul cleaning procedure that the GM technitian can perform which basically is a self cleaning procedure of the valvebody solenoids and and air/fluid purge of the Valve body curcuits .. after this it will drive normal again. but i would recommend driving the truck in M4, and M5 mode until its corrected

then after this , get the circle D torque converter with OEM stall speed

What in the hell are you talking about. Every single v8 truck from 2014-2018 has this thermostat and they all operate at 190-200 degrees.

why would you post such blatantly incorrect jnfo