[DieselDrax]

So all 2018+ models should have the correct fluid? What about those members with 2018+ models complaining about shudder? Is it more than just the fluid?

No, all 2020+ models should have the correct, updated HP fluid. The TSB (https://static.nhtsa.gov/odi/tsbs/2019/MC-10163890-9999.pdf) applies to 2017-2019 model years with the 8L45 8-speed. If owners ignore the shudder then it can lead to more problems, but addressed early on it should only involve a fluid exchange to get the new fluid in.

 

[halbwissen]

Thanks for the correction, DieselDrax.

 

[gherbert]

So all 2018+ models should have the correct fluid? What about those members with 2018+ models complaining about shudder? Is it more than just the fluid?

As of July 8th, 2019, GM began using a new type of Mobil 1 automatic transmission fluid for the troublesome transmissions

https://gmauthority.com/blog/2019/08/tsb-seems-to-fix-8-speed-automatic-gm-transmission-problems/

So 2020, 2021 and 2022 models would come from the factory with the new fluid

 

[6speedTi]

Ok so the gm authority link says upgrade to the new fluid. It doesn't specify black label to blue label. It doesn't specify what was used before the upgrade. Upgrade to what? We can only assume because of all the talk on the topic going from black label to blue label.

 

[gherbert]

It was said in the TSB.

"Important: This procedure must be followed as published. The exchange process is required to obtain proper level of new blue label Mobil 1 Synthetic LV ATF HP fluid."

https://static.nhtsa.gov/odi/tsbs/2019/MC-10161881-9999.pdf

 

[WillB]

GM Part # 19418066

 

[6speedTi]

It was said in the TSB.

"Important: This procedure must be followed as published. The exchange process is required to obtain proper level of new blue label Mobil 1 Synthetic LV ATF HP fluid."

https://static.nhtsa.gov/odi/tsbs/2019/MC-10161881-9999.pdf

Ok but read page 6. On flush machine setup. It says...

"Initial TransFlow Flush Machine Setup Important: The prepping procedure only needs to be completed if the DT-45096 supply reservoir has DEXRON VI fluid in it and has not been converted to use the new blue label Mobil 1 Synthetic LVATF HP fluid. Note: The prepping procedure only needs to be completed if HP fluid is not in the supply reservoir."

I thought they went from black label to blue label. Dexron VI was before the black label? I read that the black label is compatible with blue if you don't get it all out on a drain or flush. It only mentions Dexron VI. Doesn't say to prep the flush machine from black to blue label. So what I'm trying to figure out is at some point was Dexron VI used in the 8 speed early on and then swapped to the black label and now blue label? I know GM hides information to the consumer for privacy reasons.
Now it is also possible that the flush machine was previously used to flush transmissions with Dexron VI hence the notation on flushing the machine. But you would think there would be a notation about black label being in the reservoir and how to address it before using the blue label. Ok, that's it for now.
🤔

 

[gherbert]

Ok but read page 6. On flush machine setup. It says...

"Initial TransFlow Flush Machine Setup Important: The prepping procedure only needs to be completed if the DT-45096 supply reservoir has DEXRON VI fluid in it and has not been converted to use the new blue label Mobil 1 Synthetic LVATF HP fluid. Note: The prepping procedure only needs to be completed if HP fluid is not in the supply reservoir."

I thought they went from black label to blue label. Dexron VI was before the black label? I read that the black label is compatible with blue if you don't get it all out on a drain or flush. It only mentions Dexron VI. Doesn't say to prep the flush machine from black to blue label. So what I'm trying to figure out is at some point was Dexron VI used in the 8 speed early on and then swapped to the black label and now blue label? I know GM hides information to the consumer for privacy reasons.
Now it is also possible that the flush machine was previously used to flush transmissions with Dexron VI hence the notation on flushing the machine. But you would think there would be a notation about black label being in the reservoir and how to address it before using the blue label. Ok, that's it for now.
🤔

The 2018 and 2019 used the HP Fluid and not Dexron VI like the 2017. Blue Label was the replacement for them both.

Sorry that it gave you some confusion

 

[gherbert]

Ok but read page 6. On flush machine setup. It says...

"Initial TransFlow Flush Machine Setup Important: The prepping procedure only needs to be completed if the DT-45096 supply reservoir has DEXRON VI fluid in it and has not been converted to use the new blue label Mobil 1 Synthetic LVATF HP fluid. Note: The prepping procedure only needs to be completed if HP fluid is not in the supply reservoir."

I thought they went from black label to blue label. Dexron VI was before the black label? I read that the black label is compatible with blue if you don't get it all out on a drain or flush. It only mentions Dexron VI. Doesn't say to prep the flush machine from black to blue label. So what I'm trying to figure out is at some point was Dexron VI used in the 8 speed early on and then swapped to the black label and now blue label? I know GM hides information to the consumer for privacy reasons.
Now it is also possible that the flush machine was previously used to flush transmissions with Dexron VI hence the notation on flushing the machine. But you would think there would be a notation about black label being in the reservoir and how to address it before using the blue label. Ok, that's it for now.
🤔

For more clarification:
TCC Shudder and New Mobil 1 Fluid Exchange
January 31, 2019
A new transmission fluid exchange procedure and a new formula of Mobil 1 Synthetic LV ATF HP transmission fluid have been released to address torque converter clutch (TCC) shudder conditions on 8L45 and 8L90 8-speed automatic transmissions
..............
The TCC shudder condition is related to moisture content in the transmission fluid. The current fluid tends to be hydroscopic, or absorbs moisture, which increases the chance of TCC shudder. There are three different fluid exchange procedures to follow, depending on vehicle application, so that an acceptable concentration of the new HP fluid is achieved in the transmission.
....................
The new Mobil 1 Synthetic LV ATF HP transmission fluid is now available to U.S. dealerships through your local GM Oil Distributor. The new Mobil 1 Synthetic LV ATF HP transmission fluid is available in quart bottles (GM Part Number 19417577) and, for a limited time, in 55-gallon drums (GM Part Number 19417904)

...................

TIP: Mobil 1 Synthetic LV ATF HP transmission fluid is required for all 8-speed transmission repairs regardless of the repair being completed.

Quart bottles, which can be identified by a new blue banner across the front of the bottle

TCC Shudder and New Mobil 1 Fluid Exchange – TechLink

 

[6speedTi]

The 2018 and 2019 used the HP Fluid and not Dexron VI like the 2017. Blue Label was the replacement for them both.

Sorry that it gave you some confusion

Actually you gave me the answer I was hoping for. At some point the 8 speed had Dexron VI. I'm trying to verify compatibility. If my shudder doesn't clear up after repeat draining and adding new fluid then I will switch over to the blue label Mobil 1 fluid. I just turned 13,000 miles. I doubt my TC is glazed or shot. I don't drive much on the highway.

 

[gherbert]

Actually you gave me the answer I was hoping for. At some point the 8 speed had Dexron VI. I'm trying to verify compatibility. If my shudder doesn't clear up after repeat draining and adding new fluid then I will switch over to the blue label Mobil 1 fluid. I just turned 13,000 miles. I doubt my TC is glazed or shot. I don't drive much on the highway.

Torque Convertor being the issue itself is less likely. Usualy will be fluid issue. And that is true for all the manufactures out there now

 

[DieselDrax]

No...

Black label was the first HP fluid used which caused problems. There is nothing proving they had Dex6 by mistake. The owners manual reference is a red herring.

Blue label was to mark the updated HP fluid which replaced the black label.

Sent from my SM-G986U using Tapatalk

 

[jerry455]

The 2017 8 speed did not use Dexron VI. The flushing machines can use any trans fluid. The procedure is to flush out any Dexron VI from the machine before the flushing procedure to the vehicle. GM does not want any cross contamination of fluids during the process. Trans flushing machines are commonly used for many other procedures not just for the flushing on the 8 speed.

 

[XLR8Rtech]

Actually you gave me the answer I was hoping for. At some point the 8 speed had Dexron VI. I'm trying to verify compatibility. If my shudder doesn't clear up after repeat draining and adding new fluid then I will switch over to the blue label Mobil 1 fluid. I just turned 13,000 miles. I doubt my TC is glazed or shot. I don't drive much on the highway.

Your 2019 diesel doesn’t have an 8 speed. Did you switch trucks to a V6?

 

[6speedTi]

Your 2019 diesel doesn’t have an 8 speed. Did you switch trucks to a V6?

Thanks for that information. No, I have a diesel with the 6l50. That is why I am trying to get as much information on different ATF fluids to try to solve my TC shudder. I'm in the process of doing several dump and flush and then see if that helps.

 

[McDubz]

Thanks for that information. No, I have a diesel with the 6l50. That is why I am trying to get as much information on different ATF fluids to try to solve my TC shudder. I'm in the process of doing several dump and flush and then see if that helps.

Old thread but thought I'd hop in here as my new-to-me truck is in the dealer for shudder, and I just spent some time with their transmission tech assisting with diagnostics. 2016 2.8 with 6l50, truck is already on its second TC (first replaced at 40k miles). I bought it at 48k miles and has significant shudder now at 50k.

I asked the technician who seemed quite knowledgeable, and he strongly stated that the 6 speed and 8 speed transmissions are very different, and the 6l50 should only ever run on dexron 6. The 8l's should only ever run HP. They are doing a new TC and changing the fluid out to Mobil 1 synthetic dexron 6 (not blue label HP). I imagine going to synthetic will help my new torque converter last longer, and I'm not one to go explicitly against GM parameters for fluids on my newish truck. On my vintage Porsche or 10 year old race car, sure lol.

That said, if the shudder comes back again some day on my third torque converter, and Shudder Fixx doesn't fix it, I may swap to the HP

OP, what did you end up going with?

 

[gherbert]

Old thread but thought I'd hop in here as my new-to-me truck is in the dealer for shudder, and I just spent some time with their transmission tech assisting with diagnostics. 2016 2.8 with 6l50, truck is already on its second TC (first replaced at 40k miles). I bought it at 48k miles and has significant shudder now at 50k.

I asked the technician who seemed quite knowledgeable, and he strongly stated that the 6 speed and 8 speed transmissions are very different, and the 6l50 should only ever run on dexron 6. The 8l's should only ever run HP. They are doing a new TC and changing the fluid out to Mobil 1 synthetic dexron 6 (not blue label HP). I imagine going to synthetic will help my new torque converter last longer, and I'm not one to go explicitly against GM parameters for fluids on my newish truck. On my vintage Porsche or 10 year old race car, sure lol.

That said, if the shudder comes back again some day on my third torque converter, and Shudder Fixx doesn't fix it, I may swap to the HP

OP, what did you end up going with?

Yes the 6 Speed and the 8 Speed take two different types of Transmission Fluid.

 

[ihC100-1974]

Yes theh 6 Speed and the 8 Speed take two different types of Transmission Fluid.

My 2016 Colorado Dmax transmission was never just right from new. At almost 60,000 miles it took a turn for the worse. No shudder, but 2-3 and 3-4 shifts were terrible. Extended warranty was still in effect, so I turned it over to the selling dealer. Six weeks later it was back with a new valve body.
Shifts were better but still not good. About a month later I changed the transmission filter and used Mobil 1 synthetic fluid. The improvement was immediately noticeable and improved for several days thereafter.
I can't attest to the long-term results as I sold that truck after driving it for another 10,000 miles. The shifts continued to be better than when new. Other than the fluid, the only other variable was the new filter.
I purchased one of the last 2022 Canyon AT4's with the same powertrain. Needless to say, at around 10,000 miles my GMC will receive the same treatment.

 

[DieselDrax]

My 2016 Colorado Dmax transmission was never just right from new. At almost 60,000 miles it took a turn for the worse. No shudder, but 2-3 and 3-4 shifts were terrible. Extended warranty was still in effect, so I turned it over to the selling dealer. Six weeks later it was back with a new valve body.
Shifts were better but still not good. About a month later I changed the transmission filter and used Mobil 1 synthetic fluid. The improvement was immediately noticeable and improved for several days thereafter.
I can't attest to the long-term results as I sold that truck after driving it for another 10,000 miles. The shifts continued to be better than when new. Other than the fluid, the only other variable was the new filter.
I purchased one of the last 2022 Canyon AT4's with the same powertrain. Needless to say, at around 10,000 miles my GMC will receive the same treatment.

In that 60k miles had the fluid ever been serviced? Did you tow or do frequent low-speed/off-road driving? Even replacing oxidized OEM Dex6 with fresh Dex6 results in a big improvement if your fluid is starting to get trashed, I noticed the same when I had my fluid serviced for the first time at 46k miles. Shifting wasn't bad, but I was starting to experience a harsh downshift when slowing to make turns from one street onto another. Trans shifted better than new after the service and has been perfectly fine since then (with regular fluid changes). I'm at 90k now.

 

[ihC100-1974]

In that 60k miles had the fluid ever been serviced? Did you tow or do frequent low-speed/off-road driving? Even replacing oxidized OEM Dex6 with fresh Dex6 results in a big improvement if your fluid is starting to get trashed, I noticed the same when I had my fluid serviced for the first time at 46k miles. Shifting wasn't bad, but I was starting to experience a harsh downshift when slowing to make turns from one street onto another. Trans shifted better than new after the service and has been perfectly fine since then (with regular fluid changes). I'm at 90k now.

I serviced the transmission following GM specs, so no service. I pull a 3,000 lb. trailer once a week in the summer. Approx. 20 miles round trip. Country roads only. I almost never drive in a town, much less a city.
I am not advising others to use anything other than Dex6. If Dex6 had performed properly in my new Colorado before or after the 60,000 mi. service, I would not have made the change.
My actions were planned to be a first step in a process to repair my failing transmission. Thankfully it was the only one necessary at that time.
There are numerous references within this forum that support my decision. I only wish to share my results. I have no interest in debate.