2022 Silverado 1500 LTD with 8 speed - Does anyone know what is the opening temp for the TBV

Carlos Eduardo Silva · November 27, 2023

Hi there,

I saw a lot of ppl talking about bypass the thermostat on the TBV for the 6 and 8 speed transmission and also saw a lot of ppl preferring to go by the bulletin https://static.nhtsa.gov/odi/tsbs/2021/MC-10207911-9999.pdf and replacing the entire TBV with a new one that has a lower opening temperature, but in that case it is only for 6 speed transmission and not 8 or even 10 speed.

Im trying to get what is the opening temperature of the TBV on my truck. In my case, I saw that the TBV on my truck is the 84443930, what has a different body from the ones with 6 speed.

So, Im trying to find info about my specific TBV, specially about the opening temperature. Is it the as the original 6 speed (194F) or does it have a different opening value ?

So for the only thing that I could find are few photos on internet and a number 2 (dot print) in the one installed on my truck.

I need to run some test on my truck to see how high transmissions temp will go but if I remember well it is more than 158F, so my guess is that internally it has the same 194F thermostat.

But if anyone has more info about it, please leave a comment...

Thank you....

Carlos Eduardo Silva · November 28, 2023

Some results from a drive/test:

1h driving
1h stop interval
and another 1h driving back home

Outside temp was:

57F during the first hour
and then 53F during the last 1h

No towing, pretty flat road with almost 0 up hills and speed was around 55mph~60mph.

My transmission temp was around:

175F for the first hour
170F for the second hour

In my opinion, it pretty high specially because I was not pushing truck hard and outside temp was really cold or even if I compare with engine temp that was all the time around 210F, and that is the engine where we get the fuel burning 100% of the time.

So, I guess I have the response for my first question.... for sure the opening temp IS NOT 158F and probably it is the 194F

What I dont understand is that when I look on literature about the average for a good transmission temp, most of the places will tell that 180F~200F is the good/ideal temp. And Im pretty sure those ppl understand way more than me about it BUT I just can not get it. I got 170F~175F in a cold evening, no towing anything and not speeding up.

Jay P · November 28, 2023

While I don’t know what the opening temp is for the TBV, there is nothing wrong with 175F for a trans temp. If your truck maintains temp empty but gets above 200F towing or loaded or hot outside air temp the thermostat may not be opening all the way (some fluid still bypassing the cooler).

Edited November 28, 2023 by Jay P

Carlos Eduardo Silva · November 28, 2023

I live in TX, last summer was like 2.5 months over 105F every single day, some days even over 110F. I don’t know how hot my transmission ran during it but if today it was 175F when outside was only < 60F I can imagine it was over 200F. That scary me.

I had decided to install the Sure Cool bypass solution, it is as a lot of ppl said. In the past, those trucks never had a thermostat and they used to have a more reliable transmission than today with the TBV.