Tbounds

I spoke with my service manager today about the problem and he was familiar with it and said most of the time they can flush transmission ,replace filter and fill with full synthetic fluid and the problem goes away.

Thanks it is annoying

2017 6.2 Denali 14k Miles I have noticed that I get this vibration on highway. It seems to me it is like a shudder when engine is lugging like it needs a leer gear . I started leaving in manual position and every time it would start vibration I would done shift to 7 from 8. The vibration would go away , then shift back to 8 and it would shudder in cycles until either accelerated or or manually down shifted anyone have this problem I believe it is transmission