transmission problems

[pathydown]

hey guys i have a 1997 nissan pathfinder. It is just the base model nothing special but the automatic transmission went out one day and after doing some self diagnosis i decided i just needed to buy a new transmission. the old transmission would move the vehicle at an idle and that was it. if i gave it gas it would seem to kick out of gear forward or reverse.. so i bought another transmission and when i pulled the old one out i had noticed that there where no torque converter bolts in the transmission at all! which would explain the knocking noise at low speed.. my torque converter had grind marks and so did my fly wheel.. just wondering if any one has had the similar problem? or was it just that the previous owner that re did the rear main f*** it up? thanks