2022 AT4 Transmission Hesitation and/or Shudder?

[OSXROB]

Well I am happy to report. That I recently got my truck back and it’s fixed.  I have been testing it for the last day or so and it’s working great.  

[Steve-2019]

1 hour ago, OSXROB said:

Well I am happy to report. That I recently got my truck back and it’s fixed.  I have been testing it for the last day or so and it’s working great.  

 

Exactly what did the dealership do to fix it for you?

[OSXROB]

They replaced the transmission control valve. 

[ajs800]

7 hours ago, OSXROB said:

They replaced the transmission control valve. 

Interesting...I will definitely be mentioning this to my dealer.  

 

I did a ride along with my dealer tech today while truck connected to his computer and it clearly is showing major slipping 5-10 times more than the acceptable level.  Goes back next week as they plan to pull the tranny and inspect all again.  We at least  determined 100% that it's tranny/torque converter  and not engine related.  a little frustrating since all this has been replaced but will hope for the best next week. 

 

[OSXROB]

UPDATE - Must return it to the dealer Monday, the hesitation/shudder is back.

Edited August 21, 2022 by OSXROB

[ajs800]

18 hours ago, OSXROB said:

UPDATE - Must return it to the dealer Monday, the hesitation/shudder is back.

 

not good to hear...I planned on mentioning the control valve to my dealer as I'm not sure if it part of the tranny replacement process or not.  Was hoping maybe that was the underlying issue with mine but probably not given yours is now back.  Are the issues exactly the same as before or there but not as severe?  I also sent you a PM. 

 

[David Krueger]

Just Sold my 2017 Colorado with a 2.8L Turbo Diesel. It developed shutter shift at about 50,000 miles. My dealer didn't want to take care of the problem. " You don't have the transmition that is under a service update, It has a 75,000 mile warrenty though." So I did some research and found that the tranny fluid was mixing with condensation and ruining it's viscosity. Dealer said that it would change the fluid for $500! Nope!  The fluid that I found on the internet that replaced the oem fluid is Mobil 1 synthetic LV ATF HP Dexron. So I bought the fluid and went to my local service garage. He did a tranny flush and put in the new fluid. Total cost $185.00. The shutter shift problem was gone instantly. Just saying maybe look in that direction before taking everything apart.

  I replaced the Colorado with a 2021 GMC Sierra 1500 AT4 3.0L Diesel. I am noticing some shifting irregulatitys. About 8,000 miles. Fuel mileage is about 21-26 MPG. Yesterday I noticed that my check engine light is on and mileage suddenly dropped to 15 mpg. So the mileage drop I think might be a regen cycle. My last truck did that and my mileage suffered a big hit too. I have a reader for the code so when I plugged it in it gave me a code P3196. and U067C 

Anyone know what those are? I have a guy that can figure it out but I hate bothering him because he is always busy.

Thanks Dave

[ajs800]

On 8/21/2022 at 5:22 PM, OSXROB said:

UPDATE - Must return it to the dealer Monday, the hesitation/shudder is back.

Any update since taking it back to dealer?  My apt got moved to this week due to not having a loaner available.  It sounds like they'll be removing the tranny again and inspecting everything related to the drivetrain.  

[OSXROB]

The service dept said they could not reproduce the condition.  I drove it home and it shuddered.  Then my wife used it once I got it home and she said it shuddered.  I plan  to use it a bit and return it again. Just disappointed at this point.  

[diyer2]

On 7/26/2022 at 6:43 AM, dutch724 said:

I had that issue in my 2017 around 60k miles. I had the mechanic replace ALL the fluid with Amzoil. No more issues. Its might be worth a shot.

I would do this right away if I had this trans.

[customboss]

1 hour ago, OSXROB said:

The service dept said they could not reproduce the condition.  I drove it home and it shuddered.  Then my wife used it once I got it home and she said it shuddered.  I plan  to use it a bit and return it again. Just disappointed at this point.  

If your dealer is like most they will blame the issue on Amsoil and it has a history of 5-10% more slippage than normal so I’d make em fix it first with the M1 LV HP since it’s a step up from Dexron 6. If fresh fluid even Dex 6 didn’t stop it very long it’s clutch’s are damaged. My opinion. 

[Black02Silverado]

On 8/17/2022 at 9:59 AM, ajs800 said:

Well, after a new torque converter, new 10spd tranny, new motor mounts , shutter /misfire (almost like a tranny slipping feel with light throttle) still present. Not sure what else to do… dealer has no clue and agrees there’s something wrong. No codes and everything monitored seems within specs.  
 

 

I wonder if it might be something in the tune. I know they all have the same one but maybe when the DFM is trying to kick in it is causing other issues but not throwing any codes. 

[ajs800]

On 8/28/2022 at 3:41 PM, Black02Silverado said:

I wonder if it might be something in the tune. I know they all have the same one but maybe when the DFM is trying to kick in it is causing other issues but not throwing any codes. 

I have wondered this as well but during the last test drive with mechanic while connected to computer, DFM was not engaged and everything engine related was all normal during the slipping/shuddering.  IT also makes no difference when driving in L9.  During the 15 mile drive, the tranny most of the time was showing additional slipping RPMs well  over 5x the acceptable limit.  He believe something was missed when installing the new tranny 2wks ago and is tearing into this week.  

[GMCustomerService]

On 8/23/2022 at 9:04 AM, David Krueger said:

Just Sold my 2017 Colorado with a 2.8L Turbo Diesel. It developed shutter shift at about 50,000 miles. My dealer didn't want to take care of the problem. " You don't have the transmition that is under a service update, It has a 75,000 mile warrenty though." So I did some research and found that the tranny fluid was mixing with condensation and ruining it's viscosity. Dealer said that it would change the fluid for $500! Nope!  The fluid that I found on the internet that replaced the oem fluid is Mobil 1 synthetic LV ATF HP Dexron. So I bought the fluid and went to my local service garage. He did a tranny flush and put in the new fluid. Total cost $185.00. The shutter shift problem was gone instantly. Just saying maybe look in that direction before taking everything apart.

  I replaced the Colorado with a 2021 GMC Sierra 1500 AT4 3.0L Diesel. I am noticing some shifting irregulatitys. About 8,000 miles. Fuel mileage is about 21-26 MPG. Yesterday I noticed that my check engine light is on and mileage suddenly dropped to 15 mpg. So the mileage drop I think might be a regen cycle. My last truck did that and my mileage suffered a big hit too. I have a reader for the code so when I plugged it in it gave me a code P3196. and U067C 

Anyone know what those are? I have a guy that can figure it out but I hate bothering him because he is always busy.

Thanks Dave

This is certainly not what we like to hear, David Krueger.  Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your 2021 GMC Sierra 1500 AT4. To do so, please send an email to [email protected] with ATTN: David Krueger/GM Trucks in the subject line.

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[ajs800]

Well, I got the truck back and again no improvement.  I am pretty much done...I've been dealing with this since the 14kmile mark.  I talked to the tech and he doesn't understand as well and after changing the fluid twice and inspecting everything within the drivetrain, basically has no answer and thinks it's all due to he fuel mgmt system, which we ruled out months ago as it is still bad in trailer mode and L9.  They are now saying the fuel mgmt system never really shuts off 100%. 

 

Two weeks ago the slipping 5-10 times the acceptable level is now considered "normal" by my dealer and GM engineers.   I will most likely be trading truck within the next two weeks and GM will have to continue to deal with it as anyone that drives it for more than 10min will realize something is not right.  

 

There is a reason the transmission was destroyed after 25-30k miles and I know the new tranny is on a similar path as bad as it is shuddering and slipping. 

 

No improvement after the following:

Software updates

New motor mounts

New torque converter

New transmission

New rear R&P

New fluids (multiple times)

 

 

 

Edited September 6, 2022 by ajs800