7AT rev slip when shifting 4 to 5

Originally Posted by Ghostvette

This is purely a guess on my part, but usually when a trans start doing that, it means that the clutch packs inside the trans are starting to slip due to wear. What kind of service have you done on the trans? Has it had fluid changed on a regular basis? Not to be negative, but it might be time to pull the trans for a rebuild before it craps itself somewhere inconvenient.