do you mean the front bearing retainer that has 4 bolts and goes over the input shaft? I have a similar concern with my car - 3k miles ago the trans was rebuilt with a new steel front bearing retainer, new throwout bearing, new clutch fork, new pivot, centerforce dual friction clutch, re-surfaced flywheel etc.... everything seems normal under the car - bolts, mounts, u-joints, 12mm drive shaft bolts, etc... but quite a bit of the time I will get a clunk sound/feel in the floor when starting off easily in first or easily in reverse - just parking lot type stuff - not showing off.. it is bothersome because I am just waiting to break something....