possible tranny problem

im gettin the impression its my tranny but not 100%i was in my truck and backed out of my driveway fine..then put it in drive and started to take off.then right when the transmission was about to shift, it made this jolt where it felt like you just down shifted a 5spd from 5th to 2nd...then it did it again right after...any ideas?

Edited: 9/3/2007 3:47:22 PM by bdroppeddak

like it shifted down gears or like it revved up and slipped out of gear?

well its an auto
from the sound and way it jerked, it sounded like it revved up and then shifted down