So had I realized that this format of the 5.3 v8 matched with the 8 speed transmission I would not have bought the truck. Right from the get go the truck when cold and went through the first gear changes, the truck would get hesitant and acted like it didn't know what it wanted to do. The shift was hard and the engine lacked power. The GMC dealer replicated the problem and even pulled another brand new truck off their lot and it did the same thing. They have supposedly reported the problem to GM but so far not a word from anybody. Now its November and the truck has 3500 miles on it and it still does the same thing every time you get into it for the first time each day. I did disconnect the negative battery terminal for an hour a few months back and it seemed to help for the first couple of cold starts but within 50- 75 miles it was back to shifting hard and hesitating. I really think this is a computer issue and I cannot believe how long this issue has been going on and GM doesn't have an answer. It effects so many vehicles for a lot of years. A truck that costs as much as it does with this problem should not be allowed to be sold.

Just traded my 2017 GMC SLT PREMIUM PACKAGE for a 2018 GMC SLT PREMIUM PACKAGE due to transmission problems I will be damn if my 2018 don't start having the same issues after about 800 miles just turned 1000 today and getting worst I think it's pretty bad when you pay 59,000 dollars for a truck that GM don't want to stand behind when they there are issues the dealerships will tell that. GM needs to step up to the plate and fix these issues they know they have or we all need to start driving a different truck like Ford or Dodge ones that stand behind their product.

Have had the truck in the dealer two times 1st my selling dealer they never put a mile on it. 2nd a Chevy dealer they claim to not be able to duplicate the issue. I have it on camera and recorded on odb Bluetooth torque app.

After the truck has set overnight or after a shift at work and the engine is cold when shifted into reverse it will surge like a engine with a big cam ,it will spin gravel very dangerous. In forward around 20 to 35 mph it will have a hesitation feeling until the engine is 1/4 the way warmed up . There is a TSB# 17-NA-070 for the model year 2017.

I have had a GM rep admit to me (GM is aware of the issue and are trying to find a fix) but get told they don't know how long. An internet search of GM hesitation problem will show it started in model year 2014 and still hasn't been corrected into 2018. Just get a run around of transmission is learning or operating as designed. GM has had to do buy backs for these. NOT happy below quality and no backing!!!!!

Buyer beware don't test drive a truck then dealer has already warmed up be the first to turn the key. That's how they get these trucks off the lot they let them run and warm up before the customer drives it off the lot!!!