I rolled over my 2005 to 222k last week. It's been well maintained and serviced regularly, but I am having issues with the automatic transmission now. I haven't had it diagnosed yet and I don't really know about transmissions, but it will drive normal if I keep it below 3000 rpm and then it will rev like I put it in neutral if I go above that. Sometimes it makes a grinding noise and kicks back in, but I have stopped driving it for now. I don't know what the issue could be. Is my transmission shot?