3.90 gear. Difrntal carrier. Rear. Device connecting Drive Shaft to Axle Shafts that allows for varied speeds of wheel rotation. Drive Ratio 3.90. The Differential Carrier assembly is a housing that is used to hold all of The Differential components and includes those components (Differential side & pinion gears, The ring gear, shims, washers, bearings, pinion pin, clutches etc.). ASSEMBLY, DIFFER. Center. TransAxle/motor.