Im sorry, but it is kind of funny GM 21-NA-199

Grumpy Bear · February 15, 2022

55 minutes ago, vrizrak said:

Does anyone has ran a pill flip while standing still in the traffic when it's 100F outside? For longer than 15 20 minutes?

Yes,

vrizrak · February 15, 2022

7 minutes ago, Grumpy Bear said:

Yes,

What highest temp have you noticed? I really curios to see what temp are you getting in heavy stop and go traffic. I did mine past weekend. I was getting constant 185-190 regardless of the outside temperature. Now since pill flip initially while driving I was reading about 120. After 10 min idling temp jumped to 140 ish. Then after driving 40 min at 40 50 mph it lowered to 130. Then after idling for some time I was getting 170. Outside temp that Sunday was about 55 degrees.

Now today we at 17 degrees. And during my morning commute I was getting 111. Driving on the highway lowered temp significantly. After 20 min at 70 I was reading 90.

At this point I'm not sure if that what I want to see. Another question at temp I would need to adjust fluid level?

Grumpy Bear · February 15, 2022

53 minutes ago, vrizrak said:

What highest temp have you noticed? I really curios to see what temp are you getting in heavy stop and go traffic. I did mine past weekend. I was getting constant 185-190 regardless of the outside temperature. Now since pill flip initially while driving I was reading about 120. After 10 min idling temp jumped to 140 ish. Then after driving 40 min at 40 50 mph it lowered to 130. Then after idling for some time I was getting 170. Outside temp that Sunday was about 55 degrees.

Now today we at 17 degrees. And during my morning commute I was getting 111. Driving on the highway lowered temp significantly. After 20 min at 70 I was reading 90.

At this point I'm not sure if that what I want to see. Another question at temp I would need to adjust fluid level?

Highest ever temp I saw with pill flip was about 215 F sitting for an hour on a limited access highway behind an accident on a 95 F day. High enough the fans kicked on ever few minutes. Thus it cycled between about 190 F and 215 F.

Here's a chart I post every time this gets asked. It's a few years worth of data I collected and plotted.

The X axis is air temp in F and the Y axis is ATF fluid in F

My truck has only the radiator ATF cooler. Trucks with the second cooler in the A/C unit run a bit cooler.

My 'normal' highway summer temp is between 155 and 165 F. City a bit warmer BUT much cooler than with the TBV GM put on them. As long as the transmission fluid is over about 70 F all programing for shift and TC operation is satisfied. Over 104 F spark and fuel are on 'normal' maps. Cooler is a bit richer and a little less timing.

What you are seeing and so worried about it the way transmissions have been cooled since 1963. This TBV thing is something more recent in the entire history of transmissions and worries people silly than have never 'seen' what it was FOREVER. Your transmission is fine.

vrizrak · February 15, 2022

Thanks Marty. At what temp you suggest to check level?

Grumpy Bear · February 15, 2022

3 hours ago, vrizrak said:

Thanks Marty. At what temp you suggest to check level?

With the pill flipped you don't have to worry about keeping the cooler and lines full. Just check at or above the normal hot operating temperature. For me that's around 160F or more. You still have to be at or over the cold check line however.

With the factory 192F unit over that.

With the "New" factory unit over 158 F

Both of those need the lines purged to get an accurate check.

NE18 · February 18, 2022

Transmission temperature is usually running 140 +\- 5F. It did top out at 158 today in traffic. I have noticed my engine runs 5-10F cooler now. Are others seeing that too?

palmer_df0130 · February 24, 2022

Does anybody know if the new tbv internals will swap out with the old tbv with the quick disconnect cooler lines? I have a 2014 Silverado and do not want to have to buy new cooler lines along with the new valve to make it work. Thanks.

Grumpy Bear · February 24, 2022

6 hours ago, palmer_df0130 said:

Does anybody know if the new tbv internals will swap out with the old tbv with the quick disconnect cooler lines? I have a 2014 Silverado and do not want to have to buy new cooler lines along with the new valve to make it work. Thanks.

Yes they will! And will swap into the 8L and 10L TVB's as well.

palmer_df0130 · February 24, 2022

Thank you Grumpy Bear for the response. I will get the updated one on order.

KARNUT · February 24, 2022

I don’t like any diesel after 2000, I don’t buy diesel anymore. I don’t like cylinder deactivation, I don’t buy them. If they tell me I can’t pick who works on it, I wouldn’t buy it.

palmer_df0130 · February 25, 2022

Have another question, what is the torque spec for the thermal bypass valve to transmission bolt? Thanks.

mikeyk101 · February 25, 2022

I'm sure there is one and it may have been mentioned earlier in this thread but I don't think torque is as important on this. I followed nice and tight when I did mine and not ham fisted crank it on as tight as possible. Just snug it fully down and a tad more and you will be fine.

Found it. The official torque values were listed on page 4 of this thread

In the event that anyone was sitting on the edge of their seat in anticipation for the torque specs, you may now rest.
The bolt that holds the thermostat housing to the transmission case = 16 FOOT POUNDS (192 INCH POUNDS)
The bolt that holds the cooler lines to the thermostat housing = 106 INCH POUNDS (8.8 FOOT POUNDS)

https://www.gm-trucks.com/forums/topic/253735-im-sorry-but-it-is-kind-of-funny-gm-21-na-199/?do=findComment&comment=2554987

Edited February 25, 2022 by mikeyk101
Added info