Ford carrier bearing used when installing a 9" 31 spline carrier into a small bearing style 9" gear case - or a case that was originally designed to be used with a 28 spline carrier - a.k.a. "slimline bearing". 2.891" O.D., 1.780" I.D. This bearing is also used with all new 9-Plus 8" Ford traction lock and limited slip units.