FYI, just did my 2015 gmc Sierra Denali 8L90 and I was able to remove mine without having to remove the drive shaft. I used a regular ratchet. No special tools required. Great vid though.
I put this in my 6L80 half ton about the same time you posted the video. Super easy and a GREAT product. Thanks for showing the 8L90. SUPERIOR TRANSMISSION PARTS INC. are really easy to order from and quick to get parts to you.
Finally got to my install. I have an 18 Silverado with 5.3 and 8L90. I live in the NV Desert. Put on about 100 miles city/highway yesterday in 95 degree heat. Wasn’t uncommon to see mid 180’s before. My peak yesterday was 152. Freeway cruising 75ish was sitting at 145 and didn’t budge. Couldn’t be more impressed/happy with this product.
“Im not sure this 10mm bolt will take 16ft/lb..” proceeds to give it an uggadugga with a 1/2” high torque Milwaukee. I like the way you roll hahah thanks for the vid, just did mine, took maybe 15/20 min. With 6” lift plenty of room to get at with out removing drive shaft with out wobble socket 👍🏻
Just got a rebuilt transmission installed because my temperatures were getting to 230F or higher and my torque converter was breaking down indicated by the fine metal on the magnet and the unusually hard shifting. I got it back from the mechanic and it went right back up to 215 on a 10 mile highway test drive. He took it back, installed a new thermostat and next day I took it on a 30 mile test drive. While on the highway temps went up to 203F but in city driving it went up to 210F-215F again. I just bought this thing on Amazon and should be coming in 3 days. Hoping it keeps my temperatures under 190. I’ll keep you guys updated on the results + new temperatures. *2018 Silverado 1500 LS 4.3L w/ 145,000 miles*
Yeah, let us know! Wouldn’t hurt to have the cooler flushed . Just to make sure you’re getting good flow. Of all the transmissions we’ve replaced for this issue I’ve only seen 1 require the cooler replaced for no flow. But it’s possible.
@@jaycastillo9313 I’ve replaced the radiator fluid, radiator thermostat, radiator temp sensor, and lower radiator hose recently after buying this truck because the stupid dealership was “kind” enough to drop it off at my doorstep 3 hours away. Long story short when they got to my house there was no coolant due to a leak in the lower hose. Ever since I fixed those things I haven’t had any issues 15k miles. Engine temperatures are still good. AC/Heater works fine. Do you think it’s possible that there’s still lack of coolant flow in the radiator that’s causing my transmission to overheat given all of that information?
Installed and took for a 50 minute test drive. First half of the drive was on the highway 55mph and second half was in city 35-40mph. Still climbed up to 220 but took a lot longer than before. Mechanic claims to have flushed the radiator already. I’ll be picking up a tru cool 40k radiator cooler soon.
Great video! I just installed this on my 17 Silverado 1500 (6L80) and now it runs much cooler. The hottest I've seen my tranny in 90 F degree weather was 147 F. What would be the drain and fill procedure now that the fluid doesn't get to 160 F? Per GM the hot check procedure is between 160-200 F.
Good to hear! You’ll be happy you went this route. To drain and fill now all you have to do is drop the pan (recommend putting a filter in if you’re already there) and fill through the dipstick tube on the 6L80. Just fill to the cold marker while the truck is running and you can just shift through the gears and re-check. I do not remember if the exhaust has to be lowered on the 6 speed off the top of my head.
@@jaycastillo9313 I'm installing this on my 6L80 today,..saw a video showing if you drop the pan enough to sneak the filter out first, it is easier to remove without yanking on the exhaust
Great video, I just replaced mine on my 2018 Chevy Silverado crew cab, took it for a test drive and it was almost 40 degrees cooler on the same drive with the old one, and I'm in the desert southwest.
Just did this installation tonight. Very well done video. Clear and to the point. Live in Central Canada. Very noticeable temp difference right away. Runs much cooler. See how the winter works with it. Can’t wait for summer pulling next summer. 👍
Just did this on a 2021 Silverado with the 8L90. Before the mod I would regularly see temperatures 190-200. A few times I saw 250. Low miles truck but I didn’t feel comfortable with those temps. Great video, one thing I’d like to add is I was able to do the entire mod without removing the trans block/trans fluid lines. I just undid the snap ring and then followed your instructions. Figured I would try and avoid separating factory seals wherever possible. I also did the job cold to avoid losing as much fluid as possible. Lost approx 1 oz. Thanks for the great video!!!
@@kevinlister5424 I’m just here to help 🤙🏽🤙🏽. I’ve had people say they can do it on car! I’m glad it worked for you. Your transmission will thank you and so will your check book. Have a great weekend!
The oval gasket number is 23135703 and the two o-rings for the lines are 12650609. The o-rings just got added to the GM parts catalog. They used to only be serviceable by ordering all new lines. Last check parts could not locate any yet. Good luck!
I was able to use a 3/8 Torque wrench with a short extension over the top of the driveshaft no problem. It fit perfectly between the exhaust and drive-shaft. It was his method and a great how to video. But, I agree. The removal of the drive shaft was unnecessary.
I had my transmission replaced last year because of this issue. I dont think they installed a lower temp block because it still gets up to 194°. Will this void my warranty if installed?
Absolutely not. GM actually recommends all transmission that come in for any type of transmission service and/or complaint the bypass be replaced with the new lower temp bypass. The bypass will have the number 70 stamped into the bottom of it if you wanted to crawl under and check yourself. The STL010 would not void warranty either as no tech is going to pull apart your bypass to see what’s inside.
Thanks for the video….. I have a 2017 SIERRA that runs at 200 degrees, I also experience hard shift into second once it warms up to operating temp…. Will this bypass help me with hard shifting issues
What do you think about the mishimoto transmission cooler thermal bypass kit?.. I recently purchased and installed mishimoto trans cooler and did the thermal bypass delete.. temp went from 180 without the delete to 135 degrees after delete upon driving in town for 30 minutes. My question is what about in cold temperatures especially here in Central time zone?.. would this kit be good for cold temps?.
I live in the midwest as well. In cold temps the spring and check ball move so the super cold fluid can by pass. The guys at SUPERIOR TRANSMISSION PARTS INC. can explain it better just give them a call and they will answer any questions.
@@stevecampbell7620 I did put in an order on the sure cool.. I did the delete with the mishimoto thermal bypass delete that came with the cooler and went on a long highway drive and my transmission temp never went over 150 at all even after returning to and driving in town temp fluctuate between 127 to 130 some. I also noticed the shifts where smooth but honestly don't know if this is too cold since dealership told me that normal operating temps are at 180. Will be installing the sure cool bypass delete for sure and see what's the difference.
@@viixiconik No the 195 thermostat is to high, The factory designed it that way claiming better fuel economy with hotter fluid. Hotter temps=more stress on the trans. If the thermostat sticks it can wipe out your trans also. BTW I am an old retired GM tech, I did this upgrade on the used 2018 Silverado as soon as I got it .Trans temps easily went to +195 before and never go above 147 on the hottest days. 127 to 130 sounds very good.
@@stevecampbell7620 wow!.. really do appreciate you for clearing that up. I thought 120 some degrees was a little too low since I was used to seeing 180. Thanks again good sir.
@@stevecampbell7620 Gm has a updated thermostat that is supposed to open at 158 i did that but temps were still in 190s so I added a auxiliary trans cooler but temps still hit 190s put my hand on trans line and they were still cold...whats your thought. I just ordered this sure cool..but this is has me stumped I'm thinking bad thermostat
I live in Iowa and it’s pretty cold here as well. I personally remote start the truck for a few minutes before I drive it and the trans temp is usually about 20 degrees warmer than ambient temperature when I hop in. And it warms up pretty well but driving immediately brings it back down. I was working it pretty hard today and it stayed about 80 Fahrenheit while driving the about 100 while I’d get out and let it idle while I was working then right back down to 80 when I’d take off again. So to answer your original question yes I definitely still recommend this. Hope this helps!
Wondering? Could the tstat just be removed from the block housing without unbolting it from the transmission? The block is laying sideways on this 8L90 vs upright on the 6L80. Has anyone just tried sliding out the tstat then slide in a new one or the sure cool MOD. Seems like it would be less fuss with bolts and trans cooler lines etc.
@@jaycastillo9313 Thanks for the reply. Great video btw. Also wondering. Have you ever just removed the tstat block completely and attached lines directly to trans.
In actuality this is just another thermostat with another opening temperature using a ball and spring. GM also sells an optional thermostat with a much lowered opening temperature for around 60 bucks . Just another option using OEM part.
Sorry if this is a basic question most already know the answer to, what is the purpose of this bypass delete? Just trying to understand why someone would want to delete it. Thanks in advance.
The thermal bypass is basically a thermostat that opens up at 190 degrees Fahrenheit. Then you get cooler flow. These 6 & 8 speed get too hot. The torque converters can’t handle it and a lot of the time get so hot they turn blue when you pull them out. At this point your replacing the entire unit most shops won’t even touch them. GM actually just released a new bulletin October 19th. 21-NA-199 that tells you to replace the original thermal bypass and updated it with a new one that opens at 158 degrees rather than the original ones that at 190 on the 6 speeds. They list 13 symptoms it may cause. I’m sure 8 speeds will be added soon.
@@jaycastillo9313 thanks for the info Jay; for 8speed same or different PN? Is this still an issue after changing fluid with the updated Mobil1 blue label full synthetic ATF LV HP?
The bulletin reads that anytime a MYC (6 speed) is in for transmission related service to replace the thermal bypass with the updated version. So it should be done even with a fluid flush. Right now it is only for the 6 speeds. And the part number will not work because the design is different than the 8 speeds. It you can use the STL010 used in the video to completely bypass and when GM releases an updated 8 speed thermal bypass you could always install that if you wanted.
@@jaycastillo9313 thanks for explaining I was confused exactly what bypass was being used for and thought there was another step to the process. Is there any updates being this look like a yr old comment I came across your video by a comment you left on another video about changing the trans fluid because of shudder this part still the recommended way? Thanks cheers
I just had this installed in my 2015 gmc crew cab 4x4 with the 6l80, but it is running hotter not cooler i used the shift tech product part# stl010. It has gone all the way up to 217, and is back down to 189. Is it possible that the shop put the spring in backwards and that is what is causing this problem? Help
About to install this on my 2019 silverado. Noticed that once the trans temp gets to 180* the downshift when coming to a stop is brutal. My bypass is like yours where it is horzontal to the ground. I wonder if it would be possible to do the swap without removing it from the trans block. thoughts?
I think just the pellet (thermostat) inside the housing is the o Lu thing that’s technically updated. So the housing you’re going to buy and the housing you have are probably the exact same. Personally I’d just use the STL010 or the updated thermal bypass. Both just seems like more $$
Hola tengo una pregunta mi trocka cuando está fría da los primer cambio muy brusco y también cundo frenas en un semáforo cuando reduce la velocidad da un pequeño jolon es una GMC Sierra 2016 de 8 velocidad me recommended quitarle el tarmostato??
There’s always a risk but it’s slim. More risk of a blockage/restriction than a freezup. I live in Iowa and I have driven my truck when the windchill is -55 degrees and all was good. I’ve never personally had an issue. My truck is equipped with an active shutter which may help reduce the chance of a freeze up condition.
Do I have to replace the fluid after putting this on? I have a 2018 1500 Z71 with the 6L80 and I’ve noticed even in the cooler weather now it’s still getting up to 180 so I’ve been thinking about getting something like this, I’m just not really able to change the fluid on my own.
Nope, not at all. Just make sure to check the level when you’re done. On the 6L you will have a dipstick and you use do not use the fluid in the video. You use Dexron VI .
I have a 2019 new body style Silverado. Would the newer gen trucks benefit from this or did GM change the thermal bypass for these? I have the 8L90 on a 5.3. Edit: I ended up ordering one and installing it. It all fit like a glove. My trans ran around 175-185, a little cooler than the previous gen trucks. Now it barely hits 130 on the highway and 150 in town in south Texas, where it’s been 95-105 *F lately. Seems to be less clunky and smoother. Very happy with this product. Wish I could post pics on here but they changed the cooler line gaskets on the newer trucks. They are larger, green, and seem to stay up into the thermostat housing. Still the same process to install, just less likely to lose the gaskets. Thanks for the video.
in colder climate do you notice that the transmission has a firmer 2-1 down shift until it reaches temps of 100* or so? Small price to pay for longevity of the trans.
I’m not sure if the part number is the same on the new body style. But I do know they kept the TBV at 194 on the 8 speeds ONLY even the 10 speeds are at 130 degrees now. Definitely something to look into. If it were mine I’d do some research on their website.
This is NOT a solution for the smaller chevy engines that don't also have an auxiliary transmission cooler. I installed this on my 2018 Silverado with 4.3L and it had NO effect, except slowing the temperature climb. Once the truck was up to normal temp, at highway speeds my tranny was 199F. I've learned that without an auxiliary cooler, the radiator temp itself sets the tranny fluid return temperature. MFR. should indicate this in it's advertising.
Did you learn this through personal experience or did you read about it online? I have the same engine and I just purchased this thing. Don’t tell me it won’t work 😭
@@parsingh559 On any extended trip, it will NOT cool your transmission fluid lower than your radiator temperature with that truck. Without an auxiliary cooler (outside the radiator), the coldest the transmission fluid can get is the radiator temperature, which is about 195F. So if you're looking for something down in the 160F range, it won't do that with that engine. And yes, I observed this because I own the truck that did it. I looked up why and confirmed that with an internet search, it does not have an auxiliary cooler. You can still put it in, and your temps will be lower on short trips as the transmission is warming up, but if you're out for a while, the coolant temp is going to be the bottom limit on transmission fluid temp. To get the full benefit, you have to ADD an auxiliary cooler after the radiator. You can thank GM for cheaping out on this engine.
You need to take the front grill off the truck and measure the location where it would fit and then pick one of the aftermarket brands. They are dirt cheap and depending on how elaborate you want to get mounting it, pretty easy.@@parsingh559
Sorry to bug. I may have asked this before, but does anyone know the proper way to do a fluid check when this mod is done. I know with the stock equipment you have to check it between 35 and 45 Celsius or 115 F. Would anyone know the proper way to fluid check with this bypass in.
There is no waiting for the valve to open. The actual procedure requires you to get to 194 degrees Fahrenheit to open the valve then check it at operating temp of 115. Now the vavle is gone so just get it to 95-115 degrees (GM recommendation) and pull the 10mm plug (8 speed) until the fluid stops running out and torque or get 95-115 and check dipstick (6 speed)
@@jaycastillo9313 yep. That’s how I do it. All good. I had a check engine light with code PO711 for an transmission temp sensor fault happen yesterday, so I’m scared. lol. I cleared it and have been driving and it hasn’t come on again yet but will see. I have no idea what kind of job that would be to change. lol.
@@jaybilawchuk2225 I did it on my 8 speed! It’s just the temp sensor in the transmission. You just drop the pan. I think exhaust has to be loosened on both sides to get on cover clearance. Then replace the harness, the temp sensor is part of the harness and is not serviceable.
Where do i find the correct part number for the gasket on this install? Mine is a 2018 same as your video here, but i want to make sure i buy the correct gasket. Thanks for an excellent video.
Harder to get the torque wrench in after but definitely doable! Every second helps when it’s your own vehicle though! Not getting paid to work on them, are we? Thanks!!
@@AutoSteps WCT was the goal a few years ago but after being so short on help and a couple kids later it unfortunately became back burner very quickly. Good luck in your pursuit! I have nothing but respect for those who make the cut
My trans temp was getting up to 180 with this install @64F local temp. I drove it maybe 20-25 mins stop and go, stopped for an hour and then drove it 20 mins in city/freeway and got up to 180. Cause for concern or just be happy it’s still under my normal 198ish?
Definitely seems odd. I remember summer time temps here in Iowa (not pulling/hauling anything) trans would at max get into the 150~ range in stop and go then drop drastically back down once I’d hit the highway. Ambient temp well above 64 degrees.
@@jaycastillo9313 maybe I’ll try taking it out and making sure I put it in right. Just got a fluid and filter change yesterday so everything should be good otherwise
Everyone says it works just as good and it’s free! The STL010 will bypass in the event of a freeze up or blockage in the cooler or lines. That’s the advantage going that route. Hope this helps!
When installing the Superior STL010, do you happen to have the torque specs for the cooler line bolt and housing mounting bolt into the 6L80 transmission?
I have personally always just put Dexron VI back in them. That’s what GM recommends for the 6L80. Now wether someone like amsoil or Mobil makes something that they would consider an upgrade I’m an not sure on.
I plan on doing this to my 18 Sierra with 8L90 this weekend. I'm also going to be flushing and adding the blue label LVHP. Anyone know how the process will work with the bypass? I know GM hooks up to their pump to flush and pushes fluid out the cooler line
If you’re using the stl010 just simply hook the flush machine up inline and it will go. on vehicles that don’t have it deleted we disconnect the lines. Start engine, drain 3 quarts into a bucket. Then fill 3. You do this 4 times. On the fifth time you do 4 quarts. This equals 16 quarts. Then I flush the lines and top off fluid as needed. Obviously a lot harder on an 8 speed v a 6 speed.
And I know that sounds very unprofessional but that’s a actual GM procedure 😂. They even sent dealers a bucket will markings on it. They also send two adapters. One for each transmission (6&8) with hoses attached to each.
@@nolovenoah742 if you’re doing it at home I suggest getting someone to help you just turn the engine on and off. Makes it a lot easier, don’t want to lose too much fluid. If you do it alone, listen for the pump starting to whine. Turn it off as soon as you hear that and that’s about 3 to 4 quarts. Hope this helps!
@@jaycastillo9313 absolutely helps. I’ll have the old lady with me. It may be a stupid question but of course, after I do the bypass- where will the fluid drain from as I do the flush? Still check plug?
Have definitely never seen this and I have seen a ton of these things! Will post a part number for the entire assembly just in case. Thanks for your input! We’re all just here trying to save a buck and help each other out 🤙🏽
@@jaycastillo9313 yeah just do everything he did just kept it bolted to the transmission. Just took alittle hook to get the old spring out. Then put the new stuff in. Very easy
Jay do you have a small trans cooler or does your Transmittion lines go into the Radiator ? I ask because my lines go into the Radiator. And the radiator is heating up my trans gets up to about 160 to 170 after driving city on a Hot day here in Illinois. , I think I'm going to buy a trans ( its own small radiator) cooler !!!!????
I just use the factory radiator. I have seen aftermarket coolers that you hook up directly to your factory lines with rubber hoses and clamps. Thought they are not very big I’m sure a stand alone cooler is more efficient.
@@jaycastillo9313 well I ask because my engine temp is always 210. I don't like it that hot. But its ( Air quotes ) normal operating Temp. But it seems now my engine gets the Radiator 210 and that heats up my trans temp now Probably ( I'm guessing ) probably 20 ISH ° , I was just wondering why mine is running hotter than I still like at 160 - 170. BUT Granted that is much better than 200- 210. , but I was just curious if your L80 , is why it's cooler than mine. ( I think mine is the L60 ) I have a Dipstick , so I'm sure its one of the versions. 4X4 , 6 speed. But just trying to Learn all I can about it . Compaired to other Chevrolet And GMC, transmittions, so if anything ever happens to it. I know what I have. 👍💯
BUT today here just east If ST LOUIS, were about 94° outside. Its HOT HOT. , I WILL try the interstate later and see if that cools it down to where I'd like it to be. Around 135- 145. 👍👍
@@Tow_Sr. it was HOT HOT here yesterday too. I’ll be honest we’ve done so many 6 speeds and when we flush the coolers I’d say we average around .6 gallons per minute of flow. On the last 6 speed that was in our shop the tech that flushed the cooler said it flowed at 1.1 gallons per minute. So it got me thinking why that one was so much better (almost double the flow) than all the others we do? We’ve only had one that was so plugged it blew the lines off our flow machine. But also raised the question why GM warranty allows a .5 or .6 gpm flow be acceptable when they can flow up to 1.1 gpm or higher. I need to look back on that one where we replaced the cooler/radiator to see what the flow was.
I guess what I was getting at was maybe the 8 speeds coolers are bigger or have better flow. It’s rare we do 8 speeds (knock on wood) so the cooler flow rates on those are just not in my memory.
On the passenger side of the transmission there will be a heat shield with two bolts on it. Remove the heat shield and there will be a black rubber plug facing straight down into the pan. That is the fill hole. It is very tricky to get fluid into. I recommend a pump that screws into the bottle or a siphon to pull from the bottle then pump into . Be careful with the catalytic converter they get hot very fast and the vehicle needs to be running when you top off the fluid. Hope this helps.
When I look it up on the GM parts computer it doesn’t even show them as a serviceable part. They must come part of the original thermal bypass housing only. Which does us no good in this situation.
There are part numbers. GM released an updated thermal bypass that runs cooler. Google the Thermal Bypass Technical Service Bulletin and all the part numbers are on there.
Put it on a flat surface and pull the oil check plug like I do at the end of the video. If your temperature on your instrument cluster reads between the spec I gave then pull the plug and wait for the fluid to stop dripping. Then it is completely full. If you don’t get anytime when you pull the plug then yes you need to fill the transmission until it starts to come out of the check plug. Remember the vehicle must be running while you check the level
Pardon the not knowing but why not just check the dip stick? I am going to do this mod whenever the parts come in just ordered after watching your video
@@masonprine9201 His truck with 8L90 Transmission has no dipstick. What he showed on the video is the way to check the trans fluid level on 8L90 transmission.
