coleyrd1

Just got the truck back with the new transmission and it is still making the noise. Guess I will bring it back to them. It almost sounds like the sound a driveshaft makes when it is first engaged. Not sure if that makes any sense or not. I will try to get a video of it.

Its hard for me to say honestly. Probably early on but it was not very noticeable. It has recently gotten much worse over the last 5K miles or so. Dealership said yesterday they ordered a new transmission and should have it put in by middle to end of next week. It seems to be working out well so far.

I have a 2019 GMC Sierra 6.2L Denali, 10 speed transmission, with 36K miles on the truck. I have recently noticed when the truck decelerates more than 20 mph, and then if I accelerate, I hear a single bang sound coming from the transmission as soon as I start to accelerate. It is like the transmission is not prepared to go into the lower gear and jams itself into gear to accelerate. There is no delay in the acceleration that I can tell, but it is a noticeable bank or thud sound of metal on metal. Once it is in gear, it accelerates as normal, and there are no other sounds. This will only happen after the truck has warmed up 10+ min and does not happen if I decelerate less than 18-20 mph. It does not happen as often if I use the brakes to slow down. Also if I come to a complete stop it does not happen and will only happen if the truck is already in motion above 10mph or so. I took it to the local GM dealer yesterday, and they said they were not familiar with the problem, but it is definitely not right. The dealer talked with GM tech support, and GM said they have heard of the problem but did not have a solution. GM said to take out the transmission and inspect for any visual issues. If no visual issues could be found, then they would replace the transmission. Has anyone else experienced this problem? Any advice moving forward? Side note- This truck was one of the first sold in our area of the 2019 body styles. I got it in august of 2018. It had the leaking back window issue, and they replaced the window after a 2-3 month delay getting the part in and trying to fix it with sealant. Thank you in advance for your help.