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

[dieselfan1]

I had a 125 mile run and it was

-24° F here yesterday. 

15 minutes warm up.

Out the driveway trans temp +30°F

Got on the 65 mph hiway and watched it slowly climb to 72° F after about 8 miles.

Stopped for breakfast let it run the whole time. After about 30 minutes it was now up to 112°.

Stayed on the 55 mph highway and watched it drop to 84° and pretty much stayed there..

Bottom line here the trans cooler is effective.  Too effective for below zero bs.

I'm probably gonna park it when it's that cold and use my other truck.

 

[Grumpy Bear]

We were -4 or so the other day when I took off. After warm up it was running 110 F or so. Later it warmed to 10 F and it was still 110 F until I stopped for a few minutes. Hot soak took it to mid 120's where is stayed the remainder of the drive. 

 

I don't have the secondary AC ATF cooler. 

[Salsa De Piña]

I installed the new bypass valve in the middle of November.  Since then, we've had temperatures from a little above freezing down to -35°C (-31°F.)  The transmission warms up rather quickly to about 30°C (86°F,) then slowly climbs to about 60-65°C (140-150°F.)  It has not gone past 69°C (156°F).  At -30°C, it takes about a half-hour of stop-and-go city driving to get up to 60°C.  Most of this has been with myself and about 300-400 lbs of payload in the truck.

 

I have somehow managed to avoid driving out the the mother-in-law's house (about an hour outside of town) for the past two months, but I'll report back when I've got some cold highway driving.

Edited January 9, 2022 by Salsa De Piña

[steelerdude15]

Here’s a good question for anyone who has the original thermostat still installed in their truck, but flipped. While driving in colder outside temps, has anyone suffered any type of damage to their transmission due to the pill flip of the original equipment. I’m still running my truck this way. Outside temps could be anywhere from the upper 20s to the upper 40s. The temp readout will show the fluid is in the 30s or 40s when the truck is started. By the time I get to my destination using back roads, I’m at 104 F. If I use the highway or am in stop and go traffic, I hit 132 F. My truck upshifts and downshifts fine unless it has to deal with second gear which it’s always been that way. The fluid in the pan and filter were changed when the pill was flipped at 30,000 miles. 7,000 miles later, everything is still fine. I also plan on doing the 15,000 mile three quart change some have done here and plan on using Amsoil in the future as well. I know there could be moisture not burning off if the fluid doesn’t get to a certain temp. Just curious to see if anyone has had any troubles because it doesn’t seem like it so far, but I could always be wrong.

[Grumpy Bear]

15 hours ago, steelerdude15 said:

Here’s a good question for anyone who has the original thermostat still installed in their truck, but flipped. While driving in colder outside temps, has anyone suffered any type of damage to their transmission due to the pill flip of the original equipment. I’m still running my truck this way. Outside temps could be anywhere from the upper 20s to the upper 40s. The temp readout will show the fluid is in the 30s or 40s when the truck is started. By the time I get to my destination using back roads, I’m at 104 F. If I use the highway or am in stop and go traffic, I hit 132 F. My truck upshifts and downshifts fine unless it has to deal with second gear which it’s always been that way. The fluid in the pan and filter were changed when the pill was flipped at 30,000 miles. 7,000 miles later, everything is still fine. I also plan on doing the 15,000 mile three quart change some have done here and plan on using Amsoil in the future as well. I know there could be moisture not burning off if the fluid doesn’t get to a certain temp. Just curious to see if anyone has had any troubles because it doesn’t seem like it so far, but I could always be wrong.

 

Mine is still using the pill flip method. I did the pill flip in a factory thermostat on March 30, 2018 at 58,378 miles. Today she has 151,700 trouble free miles on her. At 50K I did the first trans service. R&R the pan and change the filter and started the conversion to Red Line D6 ATF. At 70,000 I installed a PML 8 quart pan with drain and continued the Red Line swap over.  I did another at 80K. Again at 100K. Once more at 127K and due again. Now 95.5% Red Line and ready for another exchange. 25K intervals from now on. 

 

On July 12, 2018, around 70K, I installed the IPSCO water thermostat and started using a Stant 180 F thermostat. 91,801 miles installed Reisch Racing 170 F water thermostat. Previous factory housing units from JET which I started using at 25K were failing as fast as I could order them. This lowered all fluid temperatures a bit more. 

 

This photo was on a 85F day on the Interstate a few  hours into the trip. Pretty average summer numbers for this truck. 

The other day in 0 F weather the trans temp was running 110 F once warmed fully and oil was 188 F.

 

 

Notes of possible difference. Pepper does NOT have a secondary transmission cooler in the AC condenser. So it runs a but warmer in winter than those that do. Also she hibernates most of the winter so miles accumulated during temperatures below 32 F are few. In the summer the trans runs as cool as those units that have secondary coolers because of the lower water thermostat. 

 

That's all the information I have on this to date. I have the new thermostat in a box here on the floor and intend to install that as soon as weather and old bones permit. I'm doing this to set a floor on the ATF temperature closer to 155 F under all conditions. 

Edited January 11, 2022 by Grumpy Bear

[dieselfan1]

14 hours ago, steelerdude15 said:

Here’s a good question for anyone who has the original thermostat still installed in their truck, but flipped. While driving in colder outside temps, has anyone suffered any type of damage to their transmission due to the pill flip of the original equipment. I’m still running my truck this way. Outside temps could be anywhere from the upper 20s to the upper 40s. The temp readout will show the fluid is in the 30s or 40s when the truck is started. By the time I get to my destination using back roads, I’m at 104 F. If I use the highway or am in stop and go traffic, I hit 132 F. My truck upshifts and downshifts fine unless it has to deal with second gear which it’s always been that way. The fluid in the pan and filter were changed when the pill was flipped at 30,000 miles. 7,000 miles later, everything is still fine. I also plan on doing the 15,000 mile three quart change some have done here and plan on using Amsoil in the future as well. I know there could be moisture not burning off if the fluid doesn’t get to a certain temp. Just curious to see if anyone has had any troubles because it doesn’t seem like it so far, but I could always be wrong.

Upper 20s to  upper 40s , I don't think there would be extra moisture build up if you're hitting 132.

It was -24° F here the other day and my pill flipped never saw more than 84°F on the highway. That's too cold to run at a long distance. I'll be doing a fluid exchange when it warms up in March April.

 

[steelerdude15]

7 minutes ago, dieselfan1 said:

Upper 20s to  upper 40s , I don't think there would be extra moisture build up if you're hitting 132.

It was -24° F here the other day and my pill flipped never saw more than 84°F on the highway. That's too cold to run at a long distance. I'll be doing a fluid exchange when it warms up in March April.

 

Yeah, I believe once the fluid temp reaches 100F or 104F, it starts to burn the moisture off. I could be wrong though.

 

On a side note, I’m a cold weather person, but I don’t know if I could handle -24F. 

[Grumpy Bear]

Water in motor oil comes mostly from combustion byproducts sneaking past the rings. Water and CO2 is what you get when hydrocarbons oxidize (burn).

 

ATF in a sealed automatic transmission no such condition exists and because of this and the layout of the transmission and it's one small vent, absorbing it from the atmosphere is minimal. Unless you submerge the vehicle past that vent ordinary fluid exchanges carried out routinely on the severe schedule will keep it from collecting. No need to worry about getting it hot enough to vaporize. 

 

That said a routine UOA would alert you to an water or glycol leaks in the radiator side cooler. If yours in all air exchange you would be less likely to have an issue with water even at very cold temperatures. 

[14burrito]

5 hours ago, Grumpy Bear said:

Water in motor oil comes mostly from combustion byproducts sneaking past the rings. Water and CO2 is what you get when hydrocarbons oxidize (burn).

 

ATF in a sealed automatic transmission no such condition exists and because of this and the layout of the transmission and it's one small vent, absorbing it from the atmosphere is minimal. Unless you submerge the vehicle past that vent ordinary fluid exchanges carried out routinely on the severe schedule will keep it from collecting. No need to worry about getting it hot enough to vaporize. 

 

That said a routine UOA would alert you to an water or glycol leaks in the radiator side cooler. If yours in all air exchange you would be less likely to have an issue with water even at very cold temperatures. 

 Yup Blackstone analysis is cheap, like $35

[Black02Silverado]

2 hours ago, 14burrito said:

 Yup Blackstone analysis is cheap, like $35

You can get an Oil Analyzers kit as well and it I believe includes TBN for the same cost.  Plus they use a better test for fuels dilution.  It is more accurate than Blackstone.

[14burrito]

42 minutes ago, Black02Silverado said:

You can get an Oil Analyzers kit as well and it I believe includes TBN for the same cost.  Plus they use a better test for fuels dilution.  It is more accurate than Blackstone.

 

I'll look into it. Just used my last Blackstone sample from bulk so may try the Amsoil analysis and compare.

[pokismoki]

if you guys are concerned with water absorbsion in oil, i found  an aftermarket product made by two companies, MotorGuard and Frantz filters, they both use toiletpaper roll or similar style roll, as a depth style filter used in bipass mode from the main oil feed. its better than the Amsoil bi-pass filter, since the TP roll is so dense and thick, it has so much surface area, very impressive simple design!

 

I found after installing it once on several engines with old dirty oil, that the the filter element actually Absorbed the water moisture in the oil. it does a very good job in grabbing dirt amd at dehydrating the oil

Edited January 12, 2022 by pokismoki

[16LT4]

Some additional "pill flip" data points:

 

Location: Hudson Valley, NY

Time: 0630

Air temperature: 26*F

 

Normally I never start the car in the morning and walk away, but I had to bring my 3 yr old to daycare before work, so I started the car, then walked back inside to get him and our gear, and walked back outside.  Not more than 5 minutes run-time.  ATF temperature when I pulled out of my driveway was 76*F, an increase of 10*F/minute.

 

Within 4 miles of 30-40mph driving with the occasional stop sign, ATF was in the mid 80*F's.  From that point, the rate of temperature-increase decreased.  Commute to day-care is 15 miles, including 2-3 miles of 70 mph 4 lane, but most is 40-50 mph 2 lane.  At the end of the 4 lane, approximately 8-9 miles in, ATF touched 90*F.  Some slower driving, and stop sign accelerations crested 100*F after 13 miles, and hit 104*F when I rolled into the day-care driveway.  I left the truck idling while I brought the dude inside, and a couple minutes later when I came back out, ATF hit 111*F, where it stayed the mile and a half to school from there.

 

I don't usually drive the truck when it's cold or in inclement weather (it's got a lot of real estate to wash, and the Bimmer has far greater rust-through protection), but I may have to on a clear, cold day just to gather data.  We typically don't see temperatures less than 0*F here, so as long as the temperature curve looks the same, I'll keep the pill flipped and not install the upgraded thermostat.

 

Edited January 13, 2022 by 16LT4

[16LT4]

On 1/13/2022 at 7:21 AM, 16LT4 said:

Some additional "pill flip" data points:

 

Location: Hudson Valley, NY

Time: 0630

Air temperature: 26*F

 

Normally I never start the car in the morning and walk away, but I had to bring my 3 yr old to daycare before work, so I started the car, then walked back inside to get him and our gear, and walked back outside.  Not more than 5 minutes run-time.  ATF temperature when I pulled out of my driveway was 76*F, an increase of 10*F/minute.

 

Within 4 miles of 30-40mph driving with the occasional stop sign, ATF was in the mid 80*F's.  From that point, the rate of temperature-increase decreased.  Commute to day-care is 15 miles, including 2-3 miles of 70 mph 4 lane, but most is 40-50 mph 2 lane.  At the end of the 4 lane, approximately 8-9 miles in, ATF touched 90*F.  Some slower driving, and stop sign accelerations crested 100*F after 13 miles, and hit 104*F when I rolled into the day-care driveway.  I left the truck idling while I brought the dude inside, and a couple minutes later when I came back out, ATF hit 111*F, where it stayed the mile and a half to school from there.

 

I don't usually drive the truck when it's cold or in inclement weather (it's got a lot of real estate to wash, and the Bimmer has far greater rust-through protection), but I may have to on a clear, cold day just to gather data.  We typically don't see temperatures less than 0*F here, so as long as the temperature curve looks the same, I'll keep the pill flipped and not install the upgraded thermostat.

 

 

Simply in the interest of collecting data (it was only $55), I'd ordered the updated 70*C thermostat and installed it yesterday.  I then took it for a test drive to log some numbers (OK, I wanted to listen to the new exhaust too).

 

The first 6-8 miles were identical to the above run, but as I was not going all the way to work, I then looped back to my house for a total drive of 15 miles.

 

Ambient air temperature: 16* F (10* colder)

 

Starting ATF temp (after a brief start-up and moving the truck up on ramps to replace the T-stat): 20*F

 

After the same 4 miles above, fluid temp was 86*F

 

After 6 miles: 95*F

 

After 8 miles: 101*F

 

When I pulled back into my driveway after 15 miles: 126*F.

 

So, with colder air temp, the ATF did get ~20% warmer, which is to be expected without flow to the cooler  This trip did NOT see the brief 4-lane highway speeds noted above, and I *may* have accelerated harder and more frequently to listen to the music.   I'll be taking the truck on a 300 mile trip this weekend for work (the forecasted snowstorm is a perfect time to spend 48 hours aboard ship) and will log some more temperature data with the updated thermostat.

 

A word of caution for anyone installing the new thermostat: mine, from GMpartsdirect, did NOT come with the o-rings for the ATF cooler lines, so I needed to transfer them from the old thermostat.  Carefully inspect your new one to verify o-ring existence. 

[mikeyk101]

3 hours ago, 16LT4 said:

....A word of caution for anyone installing the new thermostat: mine, from GMpartsdirect, did NOT come with the o-rings for the ATF cooler lines, so I needed to transfer them from the old thermostat.  Carefully inspect your new one to verify o-ring existence. 

 

No, o-rings definitely do not come with the new one. That almost bit me in the arse because I didn't verify that when I did the swap. I knew about those when I originally did the pill flip but didn't pay attention when swapping the new thermostat. One of the lines ended up reinstalled without the o-ring. I discovered it after getting off highway after about 45 miles. The trans began slipping bad when trying to go and was slamming into gear. I was able to limp it the few more miles to get home. Entire underside was coated in trans fluid. I ended up just over 4 qts down when replacing the list fluid. That sucked because I had no idea how much had been lost and had to rely on the dipstick and warming up the remaining fluid to get an accurate reading. It took a looooong time to get it squared away. Luckily also, I borrowed the wife's car and raced back up to other place where I had done the swap and by shear dumb luck, found the missing o-ring on the oil pan. 

 

So far, 2 months now since this happened and the trans seems to be OK and I dodged a bullet...

 

So I agree and can't stress this "little" detail enough, make sure the o-rings are still on the 2 cooling lines before fitting into the new thermostat.

Edited January 17, 2022 by mikeyk101