I drive a silveradp 1500 custom package with the 6 speed transmission. Whenever I am cruising around 40mph to 50mph my rpm gauge will start to bounce when just coasting. It will go up and down between 600 rpm and 1500. It only does this when coasting and also in reverse around 15 mph. It will stay bouncing until I hit the gas or brake. I just feel like these transmissions weren't tuned very good because my transmission is trying to shift into 4th gear at 35 mph and it's just so much more extra wear. Thanks
So I have a 2020 Silverado 1500 crew cab 2wd Custom with 371 miles on it. When the vehicle is in park it has a rough idle/vibration in the driver seat/front cab. The rpms are not moving at all but I can very strongly feel it idling. When I make the rpms go above 500 it goes away. This only happens when not moving in any gear. When driving, the truck is as smooth as can be.