sure sounds like a thrust bearing to me mines the same and its been that way near 60,000 k's and it hasnt failed just is a bit noisy if a mechanic told me the noise was gear roll over id knock him out only cause i know thats bull**** you can replace your throwout bearing possibly even the clutch if you want to but i havent ive got 100,000 on mine now with the original clutch still feels good and doesnt slip. if you are going to do it dont replace the rear main unless its actually leaking sounds stupid i know but seriously if its replaced its more likely to leak than if its left well alone and its rare they leak anyway.