2020 Sierra SLT shudder

[ThomasElkins]

I recently purchased a 2020 Sierra Crew Cab SLT 4x4. After about a week, I started noticing a slight shudder when at cruising speeds. Pretty much any time above 40 mph and not accelerating. I first thought it was a transmission problem, but took it to the dealer and try said there’s nothing wrong with it, nor could they feel anything unusual. I really don’t know what it is, but am leaning more toward a problem with the automatic fuel management system as the engine reduces to fewer cylinders. It is really subtle, but annoying. The engine is a 5.3L and transmission is 10 speed. Anyone else experience this? Is this really normal as the GMC tech claims?

[Kevinsgmc2020]

I’m experiencing same thing but I have a 2020 dually Sierra duramax 6.6 but with 10 speed trans. If I ease on the gas it’s almost like a bucking or like the motor is lugging. Been at dealer for three days and they are sending data to Gm engineers. Tell me I may not have truck for a week or two because there are no codes to point to the problem. Idk. I’m not a happy camper. Truck cost 90k$  and need it for work. They want to give me a loaner Acadia!! It’s a joke !!

[Dersch]

I have this issue with my truck too. 2020 trailboss 5.3/ 10 speed. Definitely notice it on highway with a vibration but notice it in the city alot from stop lights. 

 

I havent noticed it much lately but i also have 35 mts on. Changing to ATs tomorrow so ill see what its like now 

[Libertas]

I don't get a shutter per say, as much as I did with my 2016, but on my 2019 AT4, it feels like it's lagging to keep up.  Something is not right, but dealership said unable to duplicate - and noted on the RO that it didn't have stock tires or stock exhaust 

[Dersch]

1 hour ago, Libertas said:

I don't get a shutter per say, as much as I did with my 2016, but on my 2019 AT4, it feels like it's lagging to keep up.  Something is not right, but dealership said unable to duplicate - and noted on the RO that it didn't have stock tires or stock exhaust 

I put my ATs on yesterday and definitely notice the shudder/ lag. Its hard to describe. Didnt take it on highway but it almost feels like driving a manual and being one gear too high