I have a 2017 GMC Acadia Denali with around 78k miles on it. Recently when accelerating it has been jumping up a few hundred rpm when shifting. 1st to 2nd seems ok, 2nd to 3rd it jumps around 300 rpm, and 3rd to 4th it has been up to a 600 rpm jump when shifting. I have an appointment scheduled with the dealership next week since I am still covered under my certified pre-owned warranty. Looking to get an opinion from an expert on the possible cause before I go to the dealer and they try to tell me there is nothing wrong.
Well, from your description it's slipping. Who knows if the fluid has ever been changed. It's good you have a warranty, don't let them weasel out of it. (They will tell you "it's normal" while the warranty is in effect and "you need a new transmission" when the warranty expires.)
