Just had my tranny replaced and when I hit 20mph whether it's shifting from 1st to 2nd or in L it does it but not all the time. It did it with the old tranny and the new tranny and I have warranty on new tranny labor included but they said if it made the noise before the new tranny it's not the tranny but it's seems to me it is and if not why wouldn't they see anything else wrong while everything was apart like the engine and tranny mounts were junk. Anyone have this happen or know what it might/could be? It's a 2006 Acura TL