FedUpwGM

Gotcha, but mine is a 2014 and from what I can tell this applies to 2016 and later.

Ron, new member here. I’m not sure it is the torque converter. Just had my transmission and torque converter replaced on my 2014 Sierra 1500 SLT 4x4. I still get vibration from around 50 mph to about 75. It gets worse when I apply the brakes. Just had rotors replaced and wheels balanced. Still vibrating! The truck has 143k miles and this problem has only shown up since about 100k miles. had a similar problem a few years back when the truck would shake badly from about 35 MPH and above. I was told it was the driveshaft so I took it to a mechanic in Atlanta who builds drives shafts for NASCAR. He worked on it for about half a day and then reinstalled it. Still vibrated! I took it to the GM dealer in Kennesaw, Georgia where I bought it and they had their transmission shop look at it. Of course, they said I needed a new transmission and torque converter at a cost of $6000. I passed on that and took it to AAMCO transmissions on Cobb Parkway in Atlanta and they fixed it in less than 30 minutes. It only needed transmission fluid! So I’m not real motivated by taking it back to a dealer. has anyone found what the actual cause is and how to fix it? Any suggestions would be greatly appreciated!