need trans help! completely lost on this one.

i have never taken the pan off the trans, i always thought the trans was untouched but i just heard from the previous driver that the trans has had a "rebuild" in the last 2-4 years before it was in my possession, i know for a fact that the trans hasnt been touched in 2 years....also i think the term "rebuild" was just used to say "added a shift kit"