ok so my sister's 1999 Ranger (3.0 v6 4x4 auto tranny) is havin some problems. it has always kinda lurched off the line and we put in some Trans-X and that helped alot. but its had probably about 5000-6000 miles put on it since then. she moved out to ohio so i cant drive it myself but she says that lately its been doin a real similar thing while she's just driving down the road. it kinda shakes and lurches when she gets on the gas. im not real sure wut it could be but i assume it has something to do with the tranny. any ideas?

 

i really need some input on this ASAP.
thanx!