Is it when you're letting the motor rev out of gear or shifting at higher rpm? If so, it's in the shifter and I've been told by 3 different sources that it's unfixable and all of them do it eventually - well this is for the V8s at least. I call bullshit but have not found anyone who can fix it - had the shifter replaced too and no luck. Not sure if a billet shifter would fix the issue - I'd assume so but have no evidence. Christ that one's annoying!