Everytime I go to stop I will put it in neutral and cruise to a stop, but a second or two after I stop it feels like someone rearends my truck. Its a pretty strong jolt that is felt and heard in the drivetrain. Its starting to do it more consistently now. My dealer wont ever look at it, I have been there 16 times now. I am thinking the only thing it could be are the synchos?? Anyone have any ideas?