down towards the outer rim 33 and provide enhanced rigidity to the preferably plastic outer member 40 the central section 36 also includes radially extending recess ribs 39 upon which the contact faces 38 38 u2032 are formed tangentially extending recess ribs 43 and an inner rim 45 which completely surrounds the recesses 44 each tangentially extending recess rib 43 attaches between respective ones of the at the inboard ends of radially extending recess ribs 39 to stiffen same likewise the inner cylindrical rim 45 attaches to each of the radially extending recess ribs 39 at their outboard ends to add additional strength thin planar ribs 51 provide additional structural radial support between the tangential rib 43 radial ribs 39 and inner rim 45 further strengthening the outer member 40 adjacent to the recesses 44 in an outer member 40 also includes a plurality of blind attachment holes 60 around the outer rim 33 for securing to the drive train component not shown blind holes 60 provide for ease of assembly of attachment bolts not shown the recesses 44 preferably includes a pocket cross dimension t 2 which is substantially equal to the lug thickness t 1 of the bonded lug 47 fig5 such that a preferable close fit is accomplished the preferred close fit that is accomplished is a conventional line to line fit well known in the relevant art the line fit is desired to minimize backlash in the.