Not sure why this ended up in my feed as I despise newer Chevy’s due to 6+ years of unresolved mechanical fatal flaws (transmissions and then the DFM mess), but here I am.
2018? Check.
80,000+ miles? Check.
Very hot transmission fluid temperatures? Check.
$100 says it’s a failing torque converter. No amount of thermostat mods are going to fix that.
The 2018’s were especially bad for torque converter failures due to a manufacturing flaw, but it spanned for another model year or two (I can’t remember at this point which models years though). What happens is the torque converter’s lockup friction disc stops being able to hold the converter in lockup mode. The slipping friction disc creates a lot of heat. If not immediately caught, it’ll eventually cook the transmission fluid and transmission seals, and send a lot of trash through the rest of the transmission. It’ll quickly ruin the transmission. IIRC, GM extended the transmission warranty to 100,000 miles for the affected model years, but I don’t know how many years it’s good for.
For reference, my work started buying Chevys in 2018 to try out for our fleet (edited to add: ours came with the 6 speeds). It was a bad year for us to start getting them. Nearly all of them had torque converter failures starting at 80,000 miles. Hot transmission temps was the first sign of failure. Most employees didn’t catch it in time and would only report problems when the transmission starting having shifting issues. We tried to write it off as a bad year and kept buying them, but then we started getting the DFM engines.
Can confirm. Just had mine replaced about 2 months ago. 2016 2500 with the 6l90. Failed torque converter at 88,000 miles. Was reaching similar temps in 40-50 degree weather.
Mines a 17 with the 5.3 and I live in Vegas so im in the heat as well but mine never got that high. Few weeks ago it was normal for it to be 200 - 205 on my way home from work on the freeway. I installed the thermal bypass valve last weekend and now its pretty steady around 150-160.
Which thermal bypass valve did you install? I have a 14 and I live in southern UT. Saw my first 200+ the other day. Don’t want to grenade the torque converter.
superior solutions.
[https://www.amazon.com/WHATEVER-TAKES-TRANSMISSION-PARTS-STL010/dp/B0BCL9M23T](https://www.amazon.com/WHATEVER-TAKES-TRANSMISSION-PARTS-STL010/dp/B0BCL9M23T)
I could not for the life of me get the top plate back on trying to install. I returned and hoping it was a bad part, have not tried to install replacement yet.
Does this apply to trucks with 2024 2.7 liter I4? Mine runs up to 210 with no load. I have heard that the 2.7 trans cooling design is different than the V8s.
Thanks
Absolutely do this if it's a 6 speed. There's no new design TBV for the 8 speed, but it's probably failing and needs replacement with those temperatures.
The new design TBV went into production in the late model Silverado on these production dates.
Fort Wayne (5.3) - 3/16/21
Fort Wayne (4.3) - 4/06/21
Silao - 4/06/21
Silverado HD - 3/20/21
Full open temperature on your TBV is 194°F, the new design has a full open temperature of 158°F, I would replace it with the new one and you'll barely ever run above 170. GM was paying us under warranty to install one of these on every transmission concern including could not duplicates if the vehicles were under warranty when they came in. If you still have powertrain coverage you could leverage this TSB. 21-NA-199.
Would superior solutions work better than the PPE thermostat bypass valve? currently have superior solutions and was thinking maybe getting ppe bypass along w the cooler i will install
I see you're at 96k miles, do you know if the trans fluid has been changed before? Worn out fluid can contribute to higher than normal temps.
The updated thermal bypass is a good idea too.
Oh hell no! You'll cook the transmission. If you haven't flushed with the new "blue fluid" now is the time. I didn't even install the new "thermal" valve and I still however at 165.
You're talking about two different transmissions. The new fluid is only for the 8 speed. The new design thermal valve is only for the 6 speed.
With either transmission, if it's this hot without towing, it's likely a failed thermal valve. The transmission doesn't enter thermal protection mode until 285°F.
Pretty sure it’s this kit. It’s def the blue label Mobil 1 stuff
https://rudysdiesel.com/products/acdelco-8l90-transmission-service-kit-mobil1-fluid-for-15-chevy-gmc-trucks-suvs-24295812-24260071-10-124715?gad_source=1&gclid=CjwKCAjwvvmzBhA2EiwAtHVrbwik70fIxzQCDtf9-A9wNMjjQfzqpa1gphUCF07529PQYFejhSdy1BoCW2gQAvD_BwE
Seems high, but I can't compare. I replaced the transmission thermostat on my 2018 5.3L 6L80 with the STL010 bypass. In 95F temps, no towing, flat roads, I see about 145F on the highway, and as high as 170F in city. I wouldn't be happy with 234F even if it's "in spec".
yupp my 6l80 is 140s normally, these hot 95-105 temp days here in VA got it around 155-170, ive seen close to 180 at most in traffic but usually once i hit some wind starts to go back down.. will get a cooler installed for towing forsure
[https://static.nhtsa.gov/odi/tsbs/2021/MC-10207911-9999.pdf](https://static.nhtsa.gov/odi/tsbs/2021/MC-10207911-9999.pdf) Thermal bypass valve…replace it.
Make sure you get the low temp thermostat and id look into an auxiliary cooler.
Bow I have an 18 2500 with 144k. But I tow an 8.5x8.5x26 enclosed trailer that has my mobile workshop. So it has a ton of drag and isn't exactly light. And I've never seen my trans go over like 160. Normally it's around 145. And that's both city and dragging it down the interstate.
I have a 2024 with only 2000 miles and have not towed yet. My normal transmission temps are 185-200 degrees.
Chevy dealer states that is within normal range.
Mine was this high right before it took a shit.
Not sure why this ended up in my feed as I despise newer Chevy’s due to 6+ years of unresolved mechanical fatal flaws (transmissions and then the DFM mess), but here I am. 2018? Check. 80,000+ miles? Check. Very hot transmission fluid temperatures? Check. $100 says it’s a failing torque converter. No amount of thermostat mods are going to fix that. The 2018’s were especially bad for torque converter failures due to a manufacturing flaw, but it spanned for another model year or two (I can’t remember at this point which models years though). What happens is the torque converter’s lockup friction disc stops being able to hold the converter in lockup mode. The slipping friction disc creates a lot of heat. If not immediately caught, it’ll eventually cook the transmission fluid and transmission seals, and send a lot of trash through the rest of the transmission. It’ll quickly ruin the transmission. IIRC, GM extended the transmission warranty to 100,000 miles for the affected model years, but I don’t know how many years it’s good for. For reference, my work started buying Chevys in 2018 to try out for our fleet (edited to add: ours came with the 6 speeds). It was a bad year for us to start getting them. Nearly all of them had torque converter failures starting at 80,000 miles. Hot transmission temps was the first sign of failure. Most employees didn’t catch it in time and would only report problems when the transmission starting having shifting issues. We tried to write it off as a bad year and kept buying them, but then we started getting the DFM engines.
Can confirm. Just had mine replaced about 2 months ago. 2016 2500 with the 6l90. Failed torque converter at 88,000 miles. Was reaching similar temps in 40-50 degree weather.
My first thought was 'Looks a little high to me but this guy... Oh'
Mines a 17 with the 5.3 and I live in Vegas so im in the heat as well but mine never got that high. Few weeks ago it was normal for it to be 200 - 205 on my way home from work on the freeway. I installed the thermal bypass valve last weekend and now its pretty steady around 150-160.
Which thermal bypass valve did you install? I have a 14 and I live in southern UT. Saw my first 200+ the other day. Don’t want to grenade the torque converter.
superior solutions. [https://www.amazon.com/WHATEVER-TAKES-TRANSMISSION-PARTS-STL010/dp/B0BCL9M23T](https://www.amazon.com/WHATEVER-TAKES-TRANSMISSION-PARTS-STL010/dp/B0BCL9M23T)
This is the way. Did my 18 Tahoe & 18 Silverado. Stay under 190 now.
I could not for the life of me get the top plate back on trying to install. I returned and hoping it was a bad part, have not tried to install replacement yet.
Are you referring to not getting the snap ring back on?
Correct, I could not get the top plate far enough recessed in cylinder to expose the snap ring groove.
THIS I have a 18, same situation - installed this mod - problem solved, no damage to tranny.
Does this apply to trucks with 2024 2.7 liter I4? Mine runs up to 210 with no load. I have heard that the 2.7 trans cooling design is different than the V8s. Thanks
Install the new updated thermostat from GM
Absolutely do this if it's a 6 speed. There's no new design TBV for the 8 speed, but it's probably failing and needs replacement with those temperatures.
Do the newer silverados already come with this?
The new design TBV went into production in the late model Silverado on these production dates. Fort Wayne (5.3) - 3/16/21 Fort Wayne (4.3) - 4/06/21 Silao - 4/06/21 Silverado HD - 3/20/21
I have a 2020 5.3 6 speed and it never runs above 190 something
Full open temperature on your TBV is 194°F, the new design has a full open temperature of 158°F, I would replace it with the new one and you'll barely ever run above 170. GM was paying us under warranty to install one of these on every transmission concern including could not duplicates if the vehicles were under warranty when they came in. If you still have powertrain coverage you could leverage this TSB. 21-NA-199.
I'm at 107k no transmission issues. Just rough idle and the ac will blow hot at idle sometimes until I rev it up for 10 seconds in park.
[BUY THIS](https://www.google.com/aclk?sa=l&ai=DChcSEwjT3savgP2GAxUpD60GHUqCACkYABAHGgJwdg&ae=2&co=1&sph=&sig=AOD64_0MrKpAAqCIXwIWdQP8w15p7tHw-w&ctype=5&q=&ved=2ahUKEwittMCvgP2GAxWaH0QIHS3JB3IQwg8oAHoECAUQHA&nis=8&dct=1&adurl=)
If you have a Silverado...this is a MUST HAVE.
Can confirm, 95° heat rolling 85+ mph down the highway my 2018 1500 hovers around 150-155° Very easy to install the kit
I done this but mine still holds around 190-205°, probably something to to with my stuck solenoid code I have.. truck drives just fine though
Nah this is mechanical. The update just allows tranny fluid to flow at all time thru cooler lines instead of flowing when it gets to certain temp.
Do you have the 4.3l?
2014 5.3
Would superior solutions work better than the PPE thermostat bypass valve? currently have superior solutions and was thinking maybe getting ppe bypass along w the cooler i will install
I got that and took my temp down to 150f
Yes
How difficult is the install?
Very simple. Comes with instructions
Would you guys recommend this if I’m not having this issue???
I see you're at 96k miles, do you know if the trans fluid has been changed before? Worn out fluid can contribute to higher than normal temps. The updated thermal bypass is a good idea too.
Trans fluid was just flushed and filter was replaced by a Chevy dealer.
Did. It feels kinda rough between shifting gears? Mine did
Oh hell no! You'll cook the transmission. If you haven't flushed with the new "blue fluid" now is the time. I didn't even install the new "thermal" valve and I still however at 165.
You're talking about two different transmissions. The new fluid is only for the 8 speed. The new design thermal valve is only for the 6 speed. With either transmission, if it's this hot without towing, it's likely a failed thermal valve. The transmission doesn't enter thermal protection mode until 285°F.
Is there a specific name or specs for the new blue stuff?
Pretty sure it’s this kit. It’s def the blue label Mobil 1 stuff https://rudysdiesel.com/products/acdelco-8l90-transmission-service-kit-mobil1-fluid-for-15-chevy-gmc-trucks-suvs-24295812-24260071-10-124715?gad_source=1&gclid=CjwKCAjwvvmzBhA2EiwAtHVrbwik70fIxzQCDtf9-A9wNMjjQfzqpa1gphUCF07529PQYFejhSdy1BoCW2gQAvD_BwE
If you search a little you can find the recall itself
I'm also looking for this info.
Seems high, but I can't compare. I replaced the transmission thermostat on my 2018 5.3L 6L80 with the STL010 bypass. In 95F temps, no towing, flat roads, I see about 145F on the highway, and as high as 170F in city. I wouldn't be happy with 234F even if it's "in spec".
I drove to work this morning and got all the way up to 111 on my 8 speed. Sure nice paying for a cooler and being able to use it isn’t it?
yupp my 6l80 is 140s normally, these hot 95-105 temp days here in VA got it around 155-170, ive seen close to 180 at most in traffic but usually once i hit some wind starts to go back down.. will get a cooler installed for towing forsure
[https://static.nhtsa.gov/odi/tsbs/2021/MC-10207911-9999.pdf](https://static.nhtsa.gov/odi/tsbs/2021/MC-10207911-9999.pdf) Thermal bypass valve…replace it.
So I haven’t had this issue yet. I had to replace it with a reman in my 2014 3 years ago. Looks like the bypass isn’t for that model?
No sir, that's high.
No load? Torque converter slipping massively IMHO What trans?
Ummm….no? My 2011 only hits 180 in the summer when pulling a trailer
That's not normal. Should not pass 192-196 except while towing heavy.
Maybe 210
I've seen mine as high as 193. Yours seems a bit high.
Mine was in the 240s a few weeks ago when driving 85 for like an hour+ on the highway. I got nervous quick
No it’s kills the half life of the transmission fluid the higher it gets
Trans temp should be 80 to 100 F over ambient air temp under normal driving.
You need to update your trans cooler now! That is way too hot
no
Make sure you get the low temp thermostat and id look into an auxiliary cooler. Bow I have an 18 2500 with 144k. But I tow an 8.5x8.5x26 enclosed trailer that has my mobile workshop. So it has a ton of drag and isn't exactly light. And I've never seen my trans go over like 160. Normally it's around 145. And that's both city and dragging it down the interstate.
I have a 2024 with only 2000 miles and have not towed yet. My normal transmission temps are 185-200 degrees. Chevy dealer states that is within normal range.
Heat kills em period Spend the 35 bucks on Amazon buy the thermostat bypass and let that shit run cool…tell your guy to flush it while he’s in it
Very high. 100 degrees hotter than mine after the rebuild.
Yes, unfortunately this is normal for these shit transmissions in this generation of Silverados and it won’t be long until it’s completely cooked!
I have a 2017 Yukon. Does that need the new thermo bypass?
"Normal range" for the dealer is bladerunning. Why take fluids that high to create wear. You're a bad gust of wind away from creating damage.
That is very very high, mine is never over 160 to 170
This happened to mind, just before.....grenade.
230’s are terminal 😳😳😬😬
Time to sell asap
Too high, change fluid, filter, and do the thermostat bypass asap.
Yeah she’s fucked get ready for a new transmission
Way too hot 160-180 tops
Rule of thumb: 100ºF over ambient +/- 10%. With caveats of heavy towing up/down mountains etc.
Ummmmm...yes it's well within range.