Well I hurt the rear end on my car 2 weeks ago and finally got around to checking it out . Well the new( 5 months old ) FMS 31 spline carrier/t loc is destroyed due to a spider gear letting go of a few teeth . I'm going with a moser spool because I'm tired of breaking shit in the rear end ! This is the second diff/carrier I've destroyed so I'm not doing it again . This is not a daily driver , track toy and it's not driven in the rain unless I get caught in it so I'm not worried about running the spool .