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Posted

It's the 5.3, and it goes to about 200-300 RPMs with auto start/stop turned off. You can feel the engine shudder and then go back to normal. After owning it for a year it just started doing this.

Posted

I'm used to it.. a jarring thud every damn cold morning. Don't even have to hit the gas when I shift from P to D.

Very disappointed with it, had dealership look at it, reset the computer, changed fluid, no difference.

Posted
I'm used to it.. a jarring thud every damn cold morning. Don't even have to hit the gas when I shift from P to D.

Very disappointed with it, had dealership look at it, reset the computer, changed fluid, no difference.
You have to let it idle for Minute or 2. If you hop in fire it up and drop it into D as you put your seatbelt on its gonna thud.

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Posted
12 minutes ago, topgear1224 said:

You have to let it idle for Minute or 2. If you hop in fire it up and drop it into D as you put your seatbelt on its gonna thud.

 

Now, I start it remotely whilst walking towards it. Much better that way.

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Posted
18 minutes ago, topgear1224 said:

You have to let it idle for Minute or 2. If you hop in fire it up and drop it into D as you put your seatbelt on its gonna thud.

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Yup, that works for me too. 

 

Heard the 2020 8-speed this issue is fixed with a slight redesign?  Correct me if I'm wrong.

 

Also, jealous the 10-speed is smooth right from the get go.  No warm up needed to avoid initial clunks.

Posted
Yup, that works for me too. 
 
Heard the 2020 8-speed this issue is fixed with a slight redesign?  Correct me if I'm wrong.
 
Also, jealous the 10-speed is smooth right from the get go.  No warm up needed to avoid initial clunks.
Kinda. It fixed through throttle limits. If you remote start it when you get in and push the start button it'll immediately idle down even if the engines ice cold.

There's also a noticeable delay if you hop in start it and immediately put it in reverse. You have to hit the gas to get it to move. Always makes me think it's broken.

it's all electronic there is no design change.

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Posted
29 minutes ago, topgear1224 said:

Kinda. It fixed through throttle limits. If you remote start it when you get in and push the start button it'll immediately idle down even if the engines ice cold.

There's also a noticeable delay if you hop in start it and immediately put it in reverse. You have to hit the gas to get it to move. Always makes me think it's broken.

it's all electronic there is no design change.

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I was reading somewhere here there did a change in the way the Stop/Start pressurized up, mechanical vs some other way.  I really don't remember clearly.  That the way the fluid pressurized was the cause of the clunk on cold days.  Again sorry to butchering this.  I tried to do a search and couldn't find the post again.  

 

Good to know it's all electronic.

 

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Posted
I was reading somewhere here there did a change in the way the Stop/Start pressurized up, mechanical vs some other way.  I really don't remember clearly.  That the way the fluid pressurized was the cause of the clunk on cold days.  Again sorry to butchering this.  I tried to do a search and couldn't find the post again.  
 
Good to know it's all electronic.
 
The clunk is typically caused by the torque converter draining overnight in combination with when you initially engage the reverse or forward gear set manufacturers like to use max line pressure to prevent slippage.

It appears at least from my research that GM has worked around that problem by forcing the engines to not idle up as aggressively and to idle down when the brake is pressed and it senses that you're about to move the gear shift.

to be honest with GM being involved in a class-action lawsuit I do not expect to see any design changes come to the 8-speed ever because doing so would admit that it was built wrong originally.

There is a known issue with the brake pedal dropping and start/stop system. They updated the calibration, it helped some. But my brakes still lack linearly and bite.

Basically my brakes have 2 settings which is drag to a slow stop were the transmission also fights it below 15miles an hour. And FULL ABS PANIC!!! There is no in-between. And seeing how easily they overheated combined with how little brake dust there is after 6k miles tells me the pads prefer to slide than grip.


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Posted

My 2018 SLT Sierra 6.2L with the 8 spd did the low speed 1st/2nd gear clunk all the way up to 32k miles when I traded it off. It was always in the back of my mind that something was wrong! I had it in for a re-flash 3 times.  Dealership said it's normal per GM Specs. I said that horse$h!t, but they wouldn't flush and drain it with new fluid. It is one of the main reasons I sold it. My best friend got a 19 Sierra SLT 6.2L with 10 spd and I was sold! 

 

This new 10 spd is the real deal and I have had no issues with it ever hesitating, fluttering, or clunking! (I AM KNOCKING ON WOOD NOW, NOT TO JINX MYSELF!!  LOL)

Posted

My 19 Sierra does the exact same thing. Going from reverse to drive it hesitates then suddenly kicks in with a jerk. Even downshifting to a stop, it jerks. Almost feels like someone has rear ended me 

Posted
On 6/30/2020 at 8:55 AM, IceOnly said:

My 19 Sierra does the exact same thing. Going from reverse to drive it hesitates then suddenly kicks in with a jerk. Even downshifting to a stop, it jerks. Almost feels like someone has rear ended me 

You have to come to a complete stop apparently, letting the tach hit zero. 

 

Mine used to do this when i would shift to fast. 

Posted

If you haven't already, we recommend reaching out to your dealership to further discuss these concerns. Our team can connect with them on your behalf. To get started, please send an email to [email protected] ATTN: Forum Username/GM Trucks with your contact information, VIN, brief description of your concern,  and preferred dealership. We look forward to hearing from you. To learn more about GM's privacy policy, please visit http://bit.ly/2h3ZUnC. 

 

Aleigha W. 
 

Posted
6 hours ago, GMCustomerService said:

If you haven't already, we recommend reaching out to your dealership to further discuss these concerns. Our team can connect with them on your behalf. To get started, please send an email to [email protected] ATTN: Forum Username/GM Trucks with your contact information, VIN, brief description of your concern,  and preferred dealership. We look forward to hearing from you. To learn more about GM's privacy policy, please visit http://bit.ly/2h3ZUnC. 

 

Aleigha W. 
 

I've tried that twice already with two different dealers, this is what I got back....

 

Hi, Vance. After speaking with your dealer, it has been found that the shift concern you are experiencing fits within the expected vehicle operation for the specific components and technology present in your Silverado. Therefore, no repairs will need to be completed at this time. Since we rely so heavily on the expertise of our dealerships to provide a proper resolution, we must stand by the dealership's decision.

 

I'm driving a $55k truck that can't shift properly.......

  • Like 3
Posted

Same here on my truck, under 10k miles, 2019.

 

What is meant by not shifting from R to D quickly?

 

Are y'all saying to go from R, to P, the D? Or R to D and hold the brake for a few seconds?

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