4L60 down, need input
hey guys, the other day i was driving to town and the tranny started slipping in 3rd gear. it only did it for a few seconds, but a few feet on down the road i foud i was unable to shift any higher than 2nd gear. i have dropped the pan, put in a new filter, changed the fluid, put in some Lucas transmission additive...still nothing but 2nd gear. is there anything that can be done to help it or have i killed it? it is under warranty...

